NZ Bits and Bytes Issue 1-07

PERSONAL COMPUT€R MA©nZIN€

1-9826

Issue No. 7, April 1983: $1.00

Micro networks .
tor- sch ools

NZ-made disk drives
for System 80/TRS 80

Winning Sinclair program

New Sord column |

plus our usual columns

:;. . .

IN JAPAN

THE NEC PC-OOOO
OUTSELLS ITS NEAREST
COMPETITOR DY 2 T0 1

HERESWHY.

The PC-8000 Personal
Computer for Professionals from
NEC. Prices including a high
resolution monitor start at 52140.
The PC-80O0 is a highly reliable
personal computer ideal for
applications in business and the
professions. It features a powerfu
BASIC, many versatile
applications packages, excellent
screen graphics, and high ease of
use. The PC-8000 can be used as
a stand-alone computer or as a
terminal attached to a host
computer.

Either a PC-8023A Dot Matrix

or a letter quality stand alone

typewriter can be attached to the
PC-8000.

THE FACTS I

PC 8001 B

PROCESSOR: ,iPC760C-l 1 2-60A compatible-,

'. MM/|

MAIN MEMORY*: 32K (32.768) hytcs Dynamic
haw Memory Heaoily extendable lofri K or lor
special appl -.Jlionn up 10 192 K.

flOM MEMORY; 24 K iVtb'Sl bytrtf minimum
mti.i'.iiiiij M it i oao ' I Basic and Machine Code
Monitor

KEYBOARD: 02 Keys typewriter style with 20- Key
"iimcric I>M. UBB«r/ii»««:r case qr-aptuc and
1C flnllrie Ouir actors, and conliol Keys. — 5
piogrtimmahla function keys ■ 2 functions each.

CLOCK: t me and date can bo *« and road "torn
programs. Keeps track of year, momti day and
the exaci time
ATTRIBUTES: User Programmable SottOn S*W
3G. SO ?? ev Bfl characters by20oi 25 lines

2*8 cuiactorsandg'aiyucsvmDob "60 ■ ico

dois graphic mc-se 6 colours {blac<t. blue red.
magenta, ween, cyan, yei-'o* or white!
in intensities, and ■.urcon attribute* (blinking,
reverse, hidden, etc.) Built in speaker

INTERFACES: F5K lystem >(:?C0. 2400 Hit.
£00 baud Standard 8- W paralte) printer Interlace.
Serial Interface •vi^h oph-jiial cable Ctrioi (RGB)
Video did MnnfKhrnmo iCcmnositn) Intotlnciw
260 Processor bus interlace.

TERMINAL MO DE: Allows the PC to operate as
an ASCII terminal The terminal mode can Dc
<!iiii:ri!ii Ircun it program or tvf the operator.

Software omu'iiiois a*Wafflo lor most ibm and

D|rxif m.unhamus.

PERIPHERALS

EXPANSION UNIT: Viuious Expanaton Units
available (or. t loppy and/or Fined Disk.
Memory Expansion, teal Trim Clocks with
priority inioirupts: Single bit Input and Output
porta. Addition Pi inter RS?32C, ana IEEE 468
interfaces Card slots uraliabte lor user delined
PCOs.

DOT MATRIX PRINTER: r-aclor teed o.
friction teed! ICO characteia'sec. bidirectional
upper viewer ease cnaia<ters. numerals, symbols
compressed, and double width character
expansion true descenders; 3-1 D-cttar act c
symbol set [maicnes POM clintiicier wit).
Proportional spacing

MASS STORAGE: Dual 525 or 8 inch floppy
disk dines cpving flS5 K bytes Df ?.!> Mbytm st Or SQC
capacity Comis Wintoesier disks at 6 11 or 20
Mbytes available- MuiSplpigrj gpow sharing c< 5,?!
men or Corviis otsk units between several
much incs

DISPLAY: M igh flosoliit.on 1? " Green Pnosphoi
htgh ftesolution (2000 piiol) Color Display

OTHER: Light Pens. CM Bod Plotters and otlwti
peripherals available

PROGRAMMING

ENVIRONMENT

DOS: NEC DCS 01 (optional) CP/M-. UCSD
p" system. Hacer DOS elc.

LANGUAGES: f-BA5IG 1 M . ■ , and
■Asscrnotcrc-f (optional) Fortran. Cobol. PL/Z
Pasoai, Lip. Basic Compilers.

AVAILABLE SOFTWARE: N in* roi . 1 „ <ng«
.avaitaejto immediately including Ben chniark*
System Word Processor, Mailing !.■$■ Manager
Various Accounting Packages including tiZ
iequii(."nii*nis. Fanning PacKiicjos. Super-Calc".

i«wi Ma«et". t /Mater" <?ic electronic

spread~Srhcel«. Bur.iiess Planning Prick agis
Database Systems- Telecommunication
Pioiucols. Eew wariai Pnelragos

NEC

Nippon Electric Co Ltd
Tokyo Japan

COMPLETE LIST OF DEALERS ON FACING PAGE.

OQSrnKlTERS
C* Dmnn ol <*m Scwuy a Con«any LWJ

4th Float. DFC Bldg. Cm Gr«y & FesltietatOA Sis, Wellington. P.O. Box 2377.

FOR FURTHER DETAILS
CONTACT YOUR NEAREST
DEALER

Aztec Management Services
29-33 College Hill
PO Box 47-182
AUCKLAND

Phone: IM) 793-496

D E 8 J Goldllnch Lid
Highbury HoitSG
65-67 Birkenhead Ave
PO Box 34-196
AUCKLAND 10

Phone (09) 483-342

Software Architects Ltd
10 Heather Street. Patnell
PO Box 9652. Newmarket
AUCKLAND
Phone. (09) 732-427

A1 Computer Services Lid

Kings Arcade. Victoria St

PO Box 1188

HAMILTON

Phone: (071) 193-000

Waikato Computer Centre

6 Princes Street

PO Box 1094

HAMILTON

Phone: (071) 393-416

Tsranakl Micro Electronics Ltd

Centre Courr Budding
Devon Street East
NEW PLYMOUTH
Phone: (067) 04-067
Pattersons Office Systems
211 Queen Street East
PO Box 979
HASTINGS
Phone: (070) 85-161

David Brice Electronics Ltd
47 Kimbolton Road
FEILDING
Phone: (063) 37-141

Hands On information Systems
35-37 Vrclorifl Street

WELLINGTON
Phone: (04) 725-224

Computers for People

35 Taranaki Street

WELLINGTON

Phone: (04) 847-668

Mainland Computers

LeinsterHoLis*
158 Lemster Road

Me rivals
CHRISTCHURCH

Phone: (03) 554-339
Intodala Systems
Sixth Floor, BNZ House
Cathedral Square
CHRISTCHURCH
Phone (03) 796-480

Ken France Electronics Ltd
40 Tatbet Street
PO Box 213
ALEXANDRA
Phone. (0294)8021

Generation Associates Ltd

320 Princes Street

PO Box 508

DUNEDIN

Phone- (024) 770-126

BITS 6 BYTES.

Hardware Reviews:

The largest selling personal
computers in Japan and USA
arrive in New Zealand ... and
we review them this month.
Chris 0'Donoghue gets his hands
on the IBM PC (Page 5) and
Shayne Doyle runs over the NEC
PC8000 (Page 8).
System 80 owners yearning for a
disk drive will be interested in
Jay Mann's review of a New
Zealand developed drive for the
System 80 (Page 10).

Sord arrives:

We add a new dimension to our
regular machine columns —
Peter Hyde updates the Pips HI
memory file, the latest release
from SORD'S personal
information processing system.

Page 30
Competition:

Here's a chance for Sinclair users
to "balance" Ecuation, the
program which won our first
competition. Wsyne Dobson, of
Karamu High Srhnnl. in
Hastings, supplies the details.

Page 33

Software Reviews:

Our team of rev ewers starts a
series of regular software reviews
by looking at Multipioy (Apple
arithmetic) and VIC-20 games.

Page 1 1
Education:

Nick Smythe dismantles the
mechanics of microcomputer
networking systems.

Pages 20-21
Farming:

Chris McLeotf asks why should
farmers use computers, and
explains how and where they can
get access to them.

Pages 17-18
Books:

Tony Lewis reviews a new
Sinclair book and Gerrtt Bahlman
&ets into computer language.

Page 29
Machine columns:

An A-Mazing game for Atari
users.

Page 22

A graphic game for the VIC.
Page 24

TRS8G/Systerns 80 columnist
Gordon Findlay learns how to live
with accidents.

Page 27

A tip for apple users
Page 35

BBC columnist Pip Forer works
on benchmarks.

Page 37

Business:

John Vargo gets down to the
final selection of a system
supplier and outlines what should
be in the contract- Next month,
he will discuss implementation of

a new system.
Micro News:

IBM reacts quickly to critiscism
and drops its prices for the new
IBM PC. This and more . . .

Pages 3,4,39

Graphics:

Pip Forer concludes his series on
graphics by leading you up the
"clip-on path" to better
graphics.

Pages 14-16
Beginners:

Gordon Findlay straightens out
loops in hrs series on BASIC.

Page 31

Sorry

Solicitors and architects stories
have been caught up in the
production cogs and have been
delayed. They will be coming up
in future issues.

PLUS:

Classifieds 38

Club News 39

Editorial 2

Glossary 40

Letters 12

Post your
subscription

today

€DITORinL

Bits and pieces

After six issues (you are reading the seventh) it is
time to answer some queries (and dare we say com-
plaints) from readers about the way we have done
things.

First off, the packaging of the magazine. That
changed last month with a switch to plastic bags
which we hope Improved the condition the magazine
arrived in (no more ironing out the creases).

Second, back copies. We ask for patience with
these. The demand was such that our copies of issue
number 2 disappeared quickly. Because of that de-
mand a special reprint (minus the covers) of 500
copies of issues 1 and 2 was done and most people
should now have the back copies requested (sorry
about the cover but the cost woutd have been too
great). This is the last time a reprint will be done so if
you want either of these two issues please hurry with
your orders.

We also request new subscribers to be patient. It is
too time consuming to process subscriptions in-
dividually as they arrive and recent demand ha? been
such that our computer has been kept very busy. So
all subscriptions start the month after they are receiv-
ed and if you wish back copies please use the order
form provided.

Reader contributions. Keep sending them in but
please don't expect them to be printed the next
month. If you article or program is not acceptable we
will return it otherwise we intend to publish it but that
might not occur for several months so keep looking.

Believe it or not we've also had complaints from
some readers that the magazine's price is too low.

Reluctantly economics says we have to agree and the
price will increase when the price frown ends. So If
you are not subscribing be in now.

Coming up in
BITS & BYTES

Business Computing

The Calc-a-likes — just what are
financial modelling, programs and
how can they help your business.

The first in a series by Pecer
Brawn which will include a look St
the popular programs such as
Visicalc.

NZ business software. John

Vargo reviews Auckland based In-
ternational Applications Ltd
"Charter" suite of business pro-
grams. Case study of a small
Business using a rnioxjconnputer
for accounting applcattons.

Hardware Review

A new release from National
Panasonic of Japan — the low
priced JR1 00.

Alternative machine code
programming — John Durham
puts the case for using machine

code monitors.

Plus columns an:
Farming
Education
Beginners

BITS & 8YTES is published monthly, except January, by Weill Sirss.
Dion Crooks and Paul Crooks. Editorial and subscriber inquiries to
Post Office Box 827. Christchurch.

ADVERTISING:

Auckland - Wandy Whitehead. Phone 794-807
Wellington - Annie Carrad: Phone 723-431

South Island - Graham Beecroft: Phone 554-265 Chch or telephone
Christchurch 66-566

EDITORIAL:

Auckland - Cathy and Setwyn Arrow: 30A Bracken Ave. Takapuna

Christchurch - P.O. Box 827 or Phone 66-566

Wellington - Shayne Doyle. 280-333 ext 892 ,W). 278-545 IH)

Production: Rofltc Browning. Graeme Patterson. LeeTeck Fgi, Janlno Worrell

Typesetting: Focal Point

Cover and Graphics: Sally Williams

Technical Editor: Chi«s O'Donoghue

Subscription rato: SH a year (11 issues! adults
$6 a year lor school pupils
Subscriptions begin from the next issue ol BITS & BVTES oflo« (nit subscription is
received.

Back copies are available (except issue* II at 91 per copy plus 50c por copy postage
end packaging.

Subscription eddressas:

When sending in su bsct i prions pfease include postal crones 'or the cities. II your label
is incorrectly addressed please send it to us with the correction marked.

Distribution inQulries: Bookshops — Gordon aid Gotch, Lid. Computer stores — direct

to the publishers.

Printed in Christchurch by D.M. Adams. Ltd,

COPYRIGHT: All articles ana programs printed in this magazine a»C copyright. They
should not be sold 0' passed on to non- subscribers in any form: printed, or in tape or
disk foimat,

LIABILITY: Although -nnerial used in SITS & 8VTES is Checked lor Accuracy, no lability
can be assumed for any losses due to The use of any material tn this magazine.

mention BITS & BYTES when contacting advertisers

MICRO N€UJS

IBM has reacted quickly to
criticism and lowered the prices
tor the recently announced I8M
PC.

The price for what IBM sees for
a typical business configuration —
128K RAM. two 320JC diskettes.
keyboard, screen, and a dot
matrix printer — has been cut
from $10,932 to S9860, a
reduction of 1 1 per cent.

As well this is post-devaluation
i.e. the recent devaluation won't
affect the price, meaning an
effective reduction of some 20 per
cent.

And those people who have
already bought IBM PCs won't be
disadvantaged. The price

reduction has been backdated to
the release of the PC in New
Zealand.

IBM has also announced the
release of 10 and 20 megabyte
hard disks. The sample business
configuration with a 10 megabyte
disk replacing one diskette will
cost S14.6O0.

* * * *

A direct competitor for the
Apple II is now in use in at least
one New Zealand school and is
expected to be on retail sale here
soon.

Selwyn College, in Auckland,
has purchased 1 5 Franklin Ace
1000s, a "99.9 pej cent Appie
compatible computer", according
to the International Sales Manager
for Franklin, Mr G.R. Treseder,
who visited Nyw Zealand last
month.

Now the Educational Trading
Society is offering the Ace 1000
at $1850 ($1890 with colour)
which is believed to undercut the
education price for the new Apple

He.

Nevertheless it does have a
numeric keypad. 15 Visicalc keys
and a built-in fan. It will be
interesting to see if a price
differential occurs on the retail

Apple Computer, Inc, has
already lost a copyright suit
against the Franklin Computer
Corporation in the United States.

"It is not a copy, it is a record
player that plays Apple music,"
said Mr Treseder.

Some of the Ace 1000s
advantages over the Apple II, such
as 64K RAM and upper and lower
case characters, have

disappeared with the release of
the Apple He.

COMPUTER OWNERS

WE WILL MARKET YOUR SOFTWARE JN N.Z.. AUSTRALIA AND THE U.S.A
ANY ORIGINAL APPLICATION OR GAMES PROGRAM WILL BE

CONSIDERED.

FOR FURTHER INFORMATION WRITE TO:

THE REMAP KABLE SOFTWARE COMPANY LIMITED.

P.O. BOX 9535. HAMILTON. N.Z.

How to buy a computer
by the numbers.

Introducing Ihe Cromemco C-1

Personal Computer. Under $5000,
Including software, and you get
more professional features and
performance for the price than wilh
any other personal compu ter on the
-market. We've got the numbers to
prove it.

The C- 1 starts with a high-
fesolution 1 2" CRT that displays 25
lines with a full 80 characters on
each line. Inside is a high-speed 2-
80A microprocessor and 64K bytes
of on-board memory. Then there's a
detached, easy-to-use keyboard
and a 5W " dfcsk drive with an
exceptionally large 39QK capacity.
That's the C- 1 0. and you won't find
another ready-to- use personal
computer that offers you more.

But hardware can't work
alone. That's why every C-1
includes software — word
processing, financial spread sheet.
investment planning and BASIC.
Hard-working. CP/M --based
software that meets your everyday

needs. Software that could cost
ovei- S2000 somewhere else. FREE
with the C- 1 The'e"s really nothing
else to buy.

Bui the C- 1 C's numbers tell
only part of the story. What they
don't say is that Cromemco is
already known for some of (ha
most reliable business and
scientific computers in the
industry . And now tor the
first time, this techic-iogy
is available in a personal
computer.

Z—80A

64K RAM

390K DISK DRIVE

12" CRT

COMPLETE SOFTWARE

$4495

Cromemco

Cromemco

Tomorrow's computers today

MCLEAN

INFORMATION TECHNOLOGY

WCKUUO

*0 Bfti H*i M-m»ttf<

MICRO N€UJS

miH KM » M MM» M »a ™ r

From previous page

Review of Franklin Ace 1000
soon.

* * * *

The Auckland branch of the
New Zealand Computer Society is
to hold a seminar "Micro-
computers for the Layperson"
from 9.30am to 3.30pm on
Saturday 23rd April at the
Architectural Conference Centre,
Auckland University. $2

admission will cover lectures,
videos, and discussions. Also on
display will be a selection of books
and computers-

For details contact Ian Mitchell
on 583-350.

* * * *

The B.B.C. computer-literacy
project in the United Kingdom has
not stopped at the end of "The
Computer Programme" series.

A second series is now on the
air in Britain called "Making the
Most of the Micro" and more are

planned.

A proposed future development
is to transmit computer programs
from the television studio to the
B.B.C. Microcomputer fn the
home using spare capacity in the
television signal (similar to
Teletext transmissions).
¥ ¥ + ¥

Wrightson NMA intends
setting up small computer bureau
operations at its branches, using
Sord microcomputers. Farmers
will be given access to typical
financial applications — cash-
flow projections, account
analysis, the ecoromics of farm
purchase and anaysts of longer-
term developments.

* * * *

Kellogg farm management
courses on the use of on-farm
computers are stil running.
Workshops are planned for May,
July and November. For further
information, contact Mr J.
Callan. Rural Development and
Extension Centre, Lincoln
College. Canterbury.

Industry seminar

The use of programmable
manufacturing equipment to
enhance the profitability of small-
batch production will be the sub-
ject Of a two end a half day
seminar in Palmerston North on

May 23-25.

The seminar will address itself
to- equipment that "works for
you" — cutting metal, producing
drawings, handling components

Topics to be covered will in-
clude computer-aided design,
computer-aided programming for
N.C. machines; C.N.C. and N.C.
machines: flexible automation,
and robotics. The main speaker on
robotics will be Dr Alex Holzer, an
Australian research scientist.

Speakers from Cable-Price
Engineering and Walker Scientific
{representing Computer Vision)
will also contribute.

Further information can be ob-
tained from: the secretary.
Department of Production

Technology. Massey University,
Palmerston North,

* SYSTEM 80 * SYSTEM 80 * SYSTEM 80 *
MEMORY EXPANSION AND DISK DRIVE

DESCRIPTION:

1 . Memory expansion. The addi lion of 32K RAM is carried
out by (he addition of a board within the computer,
powered from the computer's power supply. Full
buffering and heavy power supply filtering coupled *'iih-j
the use of Prime spec, components and top quality
I.C. sockets ensure reliable operation.

2. Disk Drive Interface. This unit is housed in the case with
Disk Drive and powered from the Disk Drive supply. All
connections to Disk Drive arc permanent and internal. Edge
Disk Drive connectors are provided foi connection to other
Disk Drives, a Parallel Printer and the SYSTEM 80 expansion
edge is repeated on the interface to allow the connection of other
SYSTEM 80 peripherals.

Six switches arc available on ihe front of the interface.

PRICE $1495.00 complete with 40 track floppy drive, DOS, manual etc.

Non standard versions subject to special quote

Write to:

Ph 62-894

940A Colombo St.

M44CL

Box 21-024
CHR1STCHURCH

Ph: 555-699

192PapanuiRd.

(•ttaWMMOMdMUtf

I II 1 1 1 II II llll II MlMimmilllH.

HARDWARC R€VI€UU

Hands on the IBM PC

By Chris O'Donoghue and easy to follow.

The machine as tested had two
five and a quarter floppy disk
drives, 64K of memory and a
monochrome display/parallel

printer interface with green on
black monitor and an eighty
character per second parallel
printer.

When turned on the IBM
personal computer performs a self
test of all system components.
Documentation

Documentation consisted of
three manuals, a technical
manual, a BASIC manual and a
general information/DOS manual
(although the technical manual is
an extra).

In general documentation was
complete, easy to understand,
with simple examples. But I did
find some inconsistencies. For
example, in the BASIC manual on
the subject of conversion from
single precision variables to
integer variables, it stated that

DASIC truncates cingl© precision

variables to integer, later in the
same section the manual stated
that BASEC rounds single
precision variables to integer (this
is in fact what it does).

The documentation comes
nicely packaged in ring binders
each with a case. All
documentation is fully indexed

Hardware

The IBM PC is based on the Intel
8088. a chip with an internal 16
bit structure and an 8 bit data bus.

Inside the system unit is 64K of
RAM, 40K of ROM (used for boot,
system check and BASIC) a
cassette interface, and room for
disk handlers. There is also a
keyboard interface.

Then comes the five expansion
slots, I feel this is carrying the
"simple system with user defined
expansion" a b't too far.

There should at least be a
display interface included with the
primitive system. Instead one of
the five expanson slots was used
for a monochrome display/parallel
printer interface costing $699,

leaving four slots to plug-in
expansion boards. Of these there
are options of up to two memory
boards (giving expansion up to
544K of RAM), a colour/graphics
display board, various

communications options.
Keyboard/Display

The keyboard has 83 keys,
including 10 function key,
numeric keypad, cursor

movement and special keys such
as a print screen key.

An 8 bit character set is easily
access able with the lower 7 bits
giving the ASCII character set.
The other 1 28 characters are
graphics characters.

The keyboard is connected to
the system unit by a spiral cable
and typing angle can be adjusted.

This is a very good keyboard
and it has a wonderful feel.

The display is green phosphor
with 25 lines by 80 characters

WE DONT JUST SELL COMPUTERS...

WE GIVE YOU ALL THE INFORMATION YOU NEED

COMMODORE + ATARI + SINCLAIR 2X81 + SIRIUS + BBC + SYSTEM flO + WIZZARD

Patrick Dunphy has over 1& years' computer programming experience and is now combining this with TV and
video technology. He can talk io you in English about your computer requirements. We also have a large
Stock of cheap colour TVs and monitors.

Programs avoJfabfe include:

i\\ Chess

Galaxians

Pilot

Moon Lander

Auckiands largast selection of programs, boots, games, programming courses, pane', all aece5sw.es., cassette*, cartridges, etc.
Business systems also avatlabln. Mail Ofders and all credit curds accepted. Hire purcnaso available.

SUFWKH BJECTRONICS

430 MT EDEN POAD. MT EDEN

TELEPHONE 605-216

PO. BOX 26C0 AUCKLAND

HHRDUJnR€ R€VI€UJ

r ^^^' ^ i'»i' " Wt**"«'^'" -J -'~ J ' J, *^-^"' JJJ * WW ' a "^ Jj ™"

„.,,,,. »n

wide.

Characters can be underlined,
blinked, set in high intensity or
reverse video. Full upper/lower
case and graphics characters are
displayed. Screen can also be set
so that typed characters are not
echoed (good for passwords etc).

Disk:

The disk drives are either 1 60K
or 320K depending on how much
money you have. They take 5%.
inch floppy diskettes and are not
too noisy. Up to 2 drives are
supported.

Software:

There is a large software base
available for the IBM. PC. These
include operating systems such as
CP/M-86 and UCSD p-system,
compilers such as BASIC,
PASCAL. FORTRAN and COBOL
and a host of packages from
VISICALC and MULTI-PLAN
through EASY WRITER to the
Business packages. Charter and
Attache, and games.

Operating System:

The operating system PC-DOS
will support one or two diskette
drives. File structure is of the type
DEVICE: FILENAME. EXTENSION
where FILENAME is up to eight
characters long and EXTENSION
is up to three characters long.

No attempt seems to have been
made to include a hierarchical
structure such as sub-directories.

Apart from handling files the
DOS does the other common
things, displaying directories,
renaming files, copying files etc.
There is also a nice line based text
editor called EDLIN which I found
very useful in changing ASCII
files.

BASICS:

BASIC on the IBM PC comes in
a confusing four versions.

1 . Cassette BASIC, included in
ROM, is a full BASIC that
handles cassette I/O, printer
output. and light per
functions.

2. Disk BASIC, loaded from disk,
it is a full superset of cassette
BASIC. In addition it handles
disk I/O, communications (if
communications interface is
present). It also has time and
date functions.

3. Advanced BASIC, is again a
superset of Disk BASIC, but

includes event trapping and
colour/graphics function (if
the colour/graphics board is
present) -
4. Compiler BASIC, an optional
compiler for $709 (not
tested).
Of these four versions I tested
the three interpreter BASICS,
These are all upwards compatible
i.e. anything written in cassette
BASIC will run on Disk and
Advanced BASICs etc, but not so
the Compiler BASIC.

I used the Advanced BASIC
most of the tine to get the widest
possible range of functions. The
BASICs are written by Microsoft
and Advanced BASIC is a superset
of standard Microsoft BASIC.

A nice feature was the event
trapping which was available for
function keys and communi-
cations events (e.g. receiving
data). This was of the form:
ON event GOSUB n
In the case of function key
event, trapping was KEY<m)

where m is in the range 1 to 10.

Communications were also
handled nicely. They were treated
like a normal file i.e. after doing an
OPEN "COM... statement
normal PRINT f* and INPUT # is all
that is needed. No INP(n) etc are
needed ■(if you have the right
Interface).

Overall IBM seems to have
made a reasonably conservative
product. The BASIC is not overly
structured, the DOS doesn't
handle complex directory
structures etc. But the lack of
major faults in this computer is
remarkable. However with the
amount of software available and
sure to be available soon this
machine should take a large share
of the market.

This is despite the price tag
(typical small business

configuration around S 10,000)
but is partly because of the label
which seems to be perhaps the
biggest selling point.

icrocomputer

Name:

Manufacturer

Processor;

Clock Speed:

RAM;.

ROM:

Input/Output:

Keyboard:

Display:

Languages:

Disk Operating?

Systems:
G rap files:

Sou
Cost:

a Options:

Peripherals;

IBM Personal Computer

IBM

tntsl 8088: ;

4 MHz

64K-544K

40K

Two 5V« inch floppy disk drives, cassette interface,

Centronics parallel printer port. Video. 5 expansion

s"ots.

83 key, auto repeat, numeric key-pad, edit

10 programmable function keys.

25, lines fey 80- characters, upper /lower case,

tmdarlinmaj blinking, reverse videos grGenJstioaphor.

Microsoft BASICs (see text} compilers for Pascal;

BASIC, Cobol, Fortran. Macro-Assembler.

PC-DOS, also CP;'M-8e ( UCSD, GP*M 80 sohcarii.

Character level graphics on system tested. With

additional Colours/Graphics board: 320 x 2<

4 Colour, qr 640x200 ZlColouftJ

Sound generator and speaker.

System as tested approx $9,000. Additional:

colour/graphics card «-- $658, Asynchronous

Communications Card ~ §313- Tr^ese prices subject

to price reduction announced late March.

Many Hardware and Software options exist.

Including : Inemq[y .expansion to 544K, SDtC

communications.

Printer, disks, other machines (e.g. laboratory
machines} through communicartions adaptors.

IT

N HFRF' the IBM of

o flciye.. Personal

Computers

For 40 years IBM lias built
up a wealth of experience and
expertise in computers.
Now that knowledge is built
into a tool for modern times:
the IBM Personal Computer.

As with any new tool, you'll want to get comfortable with
the IBM Personal Computer before putting it to serious use.
You'll have some stcp-by-step reading, but our instructional
literature involves you from the start. And the Computer is on
your side too — interacting with you as you learn. There's no
reason why you can't be executing programs and feeling good
with the results within your first week. After a month, it should
be clear that you've made a good investment, and you'll
probably be telling your friends why they should get one.

To keep up with
modern times, visit your
authorised IBM Personal
Computer dealer today -
or call at the IBM Product
Centre in Auckland,
Wellington or
Christchurch.
Ask what programs are j
available now. Get a
demonstration.
Be sure you check out the
specifications and features
that make this the IBM of
Personal Computers —
features that set it apart.
You'll find that the quality,
power — and readability
— arc what you'd expect
from IBM. The price isn't.

HELPING PEOPLE FIND THE ANSWERS

The IBM Personal Computer.
A. tool for modern times.

Whansareli MM Ibiiccm fid Co. Led Phon* 84-9"9 Auckland: B«« Shop Phone 52-860 Compmcrlxnd (NZ) Ud Phone 798-005 or 798-
ll~8. Financial Svsicms Limited Phone "89-068 «r 789-069. International otitic E(|uipmcn< Phumc 775-57-2 Hamilton: Thomson & Ward
( 19" I ) Lid. Phone 82-6" 1 ) Koto run- Thomson Ik VartI f I9~l > Ltd Plmnc *"'9-I - 2. Taurangai Hay of Plenty Office Supplies Phone 81-009
Hastings: Midland Daia ProccH-inR Phone 84-528 F«Imer*ton North: Dado* Electronic* ltd Phone 70-845 or 70-849. Wellington!
Compvwles Phone H44-H6 Pntijrci Computers Phone 731-152 Uardcom Bureau Phone "'29-028. Nelson: Geo Berry-man ti*l Phone
8 1 -489 Ch rUtchurch: Small ii.miu« Software Lid. Phone 64-6 1 "or 64-71 ".Dunedlti: Whltcoulls Ltd. Phone 7~4-l2<> lnvcrcarglll: Office
Cqulpmcm Southland Phone 8V-l4o. • IBM Prudutt Centres Auckland: Phone "'78-910, Wellington: I'hunr "29-199 Chrlwchurchi I'twnc
"92-840. Suva, FIJI: Kcllon, .Marketing Ud Phvnr $85-53$

HARDUJAR€ R€VI€UJ

NEC PC 8000

"effective
productivity

tool

#/

By Stiayne Doyle

computers

in schools.

CPU/Keyboard

One of the five
recommended for use
the NEC PC-8000 system loaned
to me for this review was a CP/M
colour business version

comprising:
•PC-8001B
console

• PC-801 1 B Memory expansion &
Interface unit

• PC-8031 B Dual floppy disk drive

• PC-8023B Graphics printer

• PC-8043B Hi-Res colour
monitor.

Price, around $8,600.

Over the week or so that I had
the machine, I grew to like it very
much, parting with it reluctantly. I
found it extremely easy to use, in
fact, within the first two hours I
had started writing this article us-
ing the CP/M Word Procesor
SELECT.

Physically, the system is similar
in size to most other business
computers in it's class, but I was
most impressed by the solid well
engineered system components.
The CPU/Keyboard unit is very
definitely designed to withstand
hard knocks and a lot of use, being
a substantial metal enclosure.
There is very little use of
lightweight plastic anywhere in
this computer system.

Unpacking and connecting the
system together took me a half
hour and the only problem I had
was with the cable between the
disks and the expansion unit —
these are edge connector types
and if not pressed firmly home
they can grip the edges of the cir-
cuit board without mating proper-
ly with the foil tracks. Apart from
this, the whole system fired up
and proceeded to load disk Basic
as soon as it was switched on.
Normally, however, this system
would be installed for you by

8

TISCO under contract to Scollays.

By stacking the disks, expan-
sion unit, a-^d monitor behind the
keyboard (remembering to
preserve ventilation airflow
space)! and sitting the printer
alongside, a, very compact in-
stallation can be achieved. This
also situates the monitor at a com-
fortable eye level.

The do-it-yourself programmer
will enjoy working with the NEC'S
Basic screen editor — I found it

very versatile, and it made writing
code so much quicker than with a
line editor. I also found I preferred
using the 40 column screen
width, with the consequent larger
character size, when programm-
ing. The display may be easily re-
formatted with the WIDTH state-
ment, and CONSOLE sets up other
display feaures,

The standard graphics facilities
are not particularly impressive,
with only 160 x 100 pixel resolu-
tion, a LINE statement, and what
are effectively SET and RESET
statements. I did, however, have
a disk of 12 machine code

Microcomputer

Name:

Microprocessor

Clock Speed:

RAM;

ROM:

Input/Output:

Keyboard:

■' : ■ ■ ■

■

Display:
^Unguages:

Graphica:

-■■

Sound:
Cost;

. : . ■ ■

■ . .:■ . : ' .'

Options:

DOS Options:

" ■ ' . . . .■:■ :

Peripherals:

Features:

.. .,-

NECPC-8001

U.PD780C-1 .(280A equivalent) ■

■4 Mtiz

32 KBytes Dynamic '

24 K Bytes for Basic and macJiihe language

Monitor

Coiotfrand B&W video-

600 baud FSK; cassette: ;■"

Paraifei Printer interface

1/0 Expansion Interface.

Full ASCII with numeric keypad, 5 ahifted^ro-

gramfnabln iiin'rtlon keys, olternaW* ehetaefer ■

set, graphics set from special graphics "shift"

key.

Format user definable — 20/25 lines per

screen, 36/40/72/80 cheracters per Una, k -.

NEC N-Busic, Z80 machine code \ assembler;

Fortran. Cobol, PUZ, Pascal. Lisp, Basic

Compiler.

V28 graphics : characters, 160 x 100 pixel
resolution, 8 colours, variable intensities. ■ |
Built in speaker.

(teste, unit cost — $2140 which includes 32K
CPU keyboard console; and Green screen
■monitor.

3 different expansion units for memory expan-
sion, adding floppy or hard disk drives/
p-8rs!ielteerial/lEEE488 I/O pons,, extra printer
pons, priority interrupt real-time clock, slots ?P*
user PCB's (printed circuit boards), tight pans.
Voice recognition units. Flat Bed Plotters, Hi-
Res graphics (640 x 200 .pixels*.
NEC .DOS, CP/M, UC;Sp p-system,
DOS;
PC-8043 Hi-Res Colour Monitor

Medium Res Colour Mojnitor
PC-8023 Dot Matrix "printef
PC-801 1 Expansion Unit ' '

Minimum cMsK interface
PC-8031 Dual mini disk drive
CORVUS Hard Disk Drives up to 20 Bytes,
Terminal Mode =■ — allows the computed to
operate as a standard terminal with emulator
software for most IBM and ether mainframes.

StOSO
5470

SI 440

ii&w

$250
$2340

HflRDU)flfl€ R€VI€W

graphics games, which

demonstrated that quite effective
dynamic displays can be
achieved!.

The LINE statement has
parameters which control colours
or, if black and white mode, video
attributes such as reverse, blink-
ing, secret, and combinations of
these. The graphics and alter-
native special character
sets, while residing in the usual
decimal 128-255 positions;, can
also be entered directly by a
special graphics shift key, and
alternative character set shift key.

Extensive print formatting
facilities using "mask" techni-
ques are available, and the same
formatting is used for writing
basic sequential disk file records.
Both sequential and random ac-
cess disk files are handled under
NEC DOS Basic, and it is quite
literally "child's play" using the
disk features.

A very extensive repertoire of
functions is offered, more than is
usual, with quite a few devoted to
conversion between the various
variable types. There are func-
tions tn convert between decimal,
octal, and hexadecimal, and in
fact, the latter two bases may be
used directly by using special
prefixes to the numbers.

Both date and time functions in-
terrogate the computer's internal
clock. Programmers used to
TRS-80 or System 80 will be glad
to see the very useful VA.RPTR
variable pointer function.

For the "die-hard" hex machine
code programmer, a basic
machine language monitor is pro-
vided, offering eight commands —
display and alter memory, load
and write tape, verify tape, go to
address, test memory, and return
to Basic.

Moving away from DIY soft-
ware, adding the RACET disk

operating system ($2501, allows
the use of keyed files, sort
utilities, etc. A Spreadsheet pro-
gram ($104>, and a Word Pro-
cessor ($130) are available.

Expanding to a full CP/M Disk
Operating System ($200), gives
access to the vast range of ap-
plications software written for
CP/M computers. These include
accounting systems (PADMEDE.
IAL, GOLDFINCH etc). Budgeting

* ". ; —

and Planning programs (Report

Manager, Supercalc, Scratchpad,

T/Maker etcl. Database manage-
ment software (DBASE II,
FMS-80, CONDOR etc). Word
Processor programs (SELECT,
BENCHMARK, WORDSTAR etc).

For more sophisticated custom
written programs, a choice of
language compilers - Basic,
Pascal, Cobol, etc.

Documentation was very well
covered, a comprehensive manual
being provided with each compo-
nent of the system, NEC Basic
reference marual and quick
reference programmers card. The
applications programs had their
own detailed manuals.

The quality of the manuals is ex-
cellent, and the only adverse com-
ment I would make is on the lack
of a detailed index in the back of
the manuals, although there is a
table of contenis at the front of
each.

Apart from this small point, I
could only really criticise this com-
puter on three counts.

Firstly, the prhter is rather noisy
in use and would benefit from ad-
ditional sound proofing. It also
emitted an *nnoying whistle
(about 9-12 Kh2) when turned on.

Enquiries established that this

peculiarity only appears in printers
manufactured up to a certain
serial number. While this printer is
bidirectional, it was tedious to find
that SELECT does not take advan-
tage of this, and only output print
in one direction.

My second gripe is minor, and
reflects the basic nature of the
standard graphics facilities. There
appears to be a limit to the number
of pixels that can be SET at any
time, and I also felt that some
form of programmable character
generator should have been
available, not to mention some
sort of "sprite" system.

The third point is of interest to
the computer hobbyist — this
machine does not have a parallel
or serial port on the basic console,
these are in the expansion units.

The business user will not,
however, bother about these lat-
ter two criticisms, and in my opi-
nion could consider this computer
a very cost effective productivity
tool. As you may gather, my
overall reaction is definitely
favourable, and I enjoyed working
with the NEC PC-8000 computer
system.

&

HRRDUUflR€ R€V1€UJ

A clever disk-drive expansion
for the System-80 b y jayd. mann

Until now, System-80 owners
wishing to expand their
computers have had to purchase
one or more adapter boxes to be
added via the expansion
connector at the back of their
keyboard unit. They can now
purchase a pair of locally made
units that provide expansion to full
memory plus disk and printer
operation in an elegant fashion.

There are two parts to the

expansion. First 48K of RAM is
installed inside the System-80
keyboard box. Second, a
combined disk drive/disk

controller box is plugged into the
expansion connector in the back,
of the System-80. (You could use
a disk drive without any memory
expansion, as I did briefly for this
review, but the software involved
in controlling disk operations is so
bulky that there won't be enough
room in your memory for many-
useful programs.)

The in-keyboard expansion is
done by thn nVvplnppn;. Mir.ro
Processor Services of

Christchurch, or by one of their
agents. This step should not put
you off, for it is an excellent way
to expand memory. They have
local agents throughout the
country. Alternatively, you could
mail them either one board from
your System-80, or the entire
computer. If an external

expansion interface is used, it
contains a great deal of circuitry
that duplicates logic, buffering,
and timing circuitry already
present inside the keyboard unit.
By using the in-keyboard memory
expansion, there is no need to
duplicate these circuits. You have
a computer that has a full
complement of memory without
any expansion board, adapters,
and extra cables.

In addition, if you install a ciock
speed-up modification, the in-
keyboard memory has no trouble
keeping up with the increased
throughput, whereas many
expansion interfaces have internal
timing circuits rigidly locked to the
standard System-80/TRS-80

clock. Such expansion units
cannot work properly with

10

computers wording at speeds.

Wait a momant. you must be
saying. What about the other
functions of an expansion
interface, such as a disk drive
controller and a parallel printer
port? The gooc news is that the
folks at Micro Processor Services.
Ltd, have come up with a
compact, well-designed expan-
sion boa rd that is built di rectly into
the base of yojr first disk drive,
No additional boxes or cabinets
are needed. A single 50-pin
parallel cable connects the
System-80 to the disk
drive/controller. The unit provides
standard parallel cable connectors
for additonal drives, a printer, and
further use of the System-80 bus.
Think of it. A single cable between
your computer keyboard and the
disk drive, and you have a
complete system that is still highly
portable.

The expansion board is not a
bare-bones design but instead
provides a nnmhpr nf refinements
not available on expansion boards
designed overseas. These are
controlled by a row of toggle
switches set underneath the disk-
drive door.

The most useful addition is the
ability to fool 1he computer into
thinking that a printer is attached
when it is not. This can be very

important for programs that
normally LPRINT at some point. If
you have just spent a long session
entering data, and then the
program jumps to an LPRINT
statement, normal System-80
computers will lock up unless a

printer is actually plugged in.
Pressing the Break key won't help;
you have to push the Reset
button, and lose all you data. The
Printer Disable switch bypasses
the LPRINTing. Your results won't
be printed (obviously, if you've no
printer!), but at least the program
will continue to run. You could, of
course, edit the entire program to
change LPRINT to PRINT
everywhere, btt one slip-up and
all is lost. fSorre but not all disk-
operating systems let you route
printer output back to the screen.
Again, this wsrks well if you

remember to do so before and not
after the computer gets hung up.)

If you do have a printer, then
the expansion unit provides a very
well designed parallel printer port.
Not only does it respond in the
System-80 "OUT FD" instruction
but also to the TRS-80 "LD
(37E8), A" instruction as well. No
switches need be thrown. This
overcomes one of the major
difficulties with the "improved"
System-80 software using a
proper Z80 "OUT"

instruction . . it is incompatible
with a large amount of TRS-80
software that tries to use the
37E8 approach.

All would be well if all printer
commands went through the ROM
routines, but because the ROM
routines are rather minimal many
advanced programs are designed
to control the printer directly.
Thus, the New Zealand-designed
board solves the problem neatly
by responding equally well to
System-80 and to TftS-8:0 printer
commands-

Two separate reset switches
are provided. One is like the
normal reset button on the back of
the computer. The other one acts
like a power-off reset. A
particularly useful switch allows
you to fool the computer into
thinking it is a non-disk system.
An annoying aspect of disk-
expanded System-80 and TRS-80
computers is that hitting the Reset
button fills the screen with
garbage while the computer waits
for the operating system to be
loaded off the disk — even if you
don't have a disk in the drive or
are operating without a drive
connected.

A Write-Protect switch blocks
transfer of data to a disk, so that
you can do certain risky
operations without putting
garbage on your disk.

Finally, room has been left for
future addition of a double-density
controller to the system. A switch
will then determine whether the
system boots up in single or in
double density. The System-80
normally starts up in single-
density. If suitable hardware is
present, it can then be switched
to double-density.

On examination of the interior,
the disk controller unit can be
seen to consist of a separate

power supply plus two well-
planned double-sided printed
circuit boards, with plenty of room
and no likelihood of heat build-up.
The two boards are stacked one
above the other, and fitted below
the MPI disk drive. The boards are
linked to each other by a 20-pin
plug-end-socket connector that
provides some of the mechanical
support for the upper board, and
will simplify any necessary
servicing. A flat cable leads
upwards internally into the
attached disk drive unit, which
has its own independent power
supply. Typical of the thought that
has gone into this unit is the
mounting of the U-shaped disk-
drive cover. In addition lo the
customary four screws, there is
a'n additional pair of screws that
serve as hinges so that the cover
can be swung up out of the way.
{For those who may be
confused about terminology, a
disk is the 5-inch flat object that
spins around inside a disk drive.
The disk drive itself is pretty
unintelligent, so the job of getting
information on and off the disk in a
form m«nningfnl to the- computer
is done by the disk controller.

You may have gathered that I'm
enthusiastic about this system. I
am. My present configuration is a
System-80 with a separate 50/40
adapter that in turn leads to an
LNW expansion board in its own
big case. From this, one cable
snakes out to the disk drive and
another to the printer. When I tried
out the MPS configuration, with
the combined disk drive/controller
box sitting on my table next to my
keyboard unit, the extra desk
space and lack of clutter was
most impressive. The operation of
the controller was, as it should be,
unobtrusive. Single-density disks
booted reliably and the printer
responded to LPRINT and LUST
commands. When i disconnected
the printer and threw the Printer-
Deselect switch, I was able to run
programs that called for LPRINTs
without the computer locking up.

This combination of in-keyboard
memory expansion plus a disk
controller built right into the first
disk drive, is not available
anywhere else in the world. It
should have a market not only in
New Zealand but overseas.

SOFTUJAR6

*MMMMSNMMMMOMMMMIMMMMM

Learning in
space

Apple Software for schools:
Multiploy. Availeble for Apple II
48K on disk. Retail $36.95.
Reviewed by Kathy Broadley.

The microcomputer as an
educational tool has not been ex-
ploited yet in New Zealand. Few
primary schools have even one
micro, so the use of this potential-
ly useful teaching aid is just a
gleam in the eye of some teacher
enthusiasts and some hopeful
parents. Perhaps this is just as
well since many of the so-called
educational packages are
technically competent but educa-
tionally doubtful. The objective of
getting the user to practise
number facts can be achieved
with 3 spirit duplicator worksheet
for a fraction of ne cost of a com-
puter program, even though the
immediate reinforcement of
knowing whether the answers are
correct is probably handled best
by the computer

Decause I have seen some poor
packages I was somewhat scep-
tical when I loaded "Multiploy",
by Paul Coletta (Reston Software,
Prentice- Ha II, distributed in New
Zealand by Whitehall Books). With
this package I was pleasantly sur-
prised. The accompanying booklet
claims that "Multiploy" "com-
bines the excitement of an arcade
game with the cnallenge of learn-
ing and practising arithmetic
skills." The target age range is
four to 14 years, "but adults like
it, too". There are three levels of
difficulty and the user chooses
from the four arithmetic opera-
tions. Within each level the speed
at which the problems must be
answered can be manipulated. A
nice feature for classroom use is
the option of low-level sound.

The arcade game aspect is
catered for in the way each pro-
blem is presented. Each problem
appears in a smiling (sp-ace)ship. If
the correct answer is entered the
ship is shot down. If the problem
ship is not destroyed, it will even-
tually start shooting back,
possibly destroying the user's
answer 'base'. Up to four pro-
blems are on the screen at once,
descending towards the 'base'.
The user is given a rank that is
determined by the number of cor-
rect responses. A perfect score at
any level attains the rank
Multiploy.

For classroom use a recordkeep-
ing feature would have enhanced
the program's value. A record of
problems incorrectly answered by
each user could be of assistance
to a teacher making decisions
about what should be taught next.
Equally useful would be an
authorising system so a teacher
could insert his/her own problems.
Perhaps future revisions of
"Multiploy" might include these
features. I also wondered whether
more traditionally-known ranks
such as Lieutenant or Admiral
might be more attractive to
children.

The instruction booklet is clear
enough for a fairly amateur
operator to handle. That's impor-
tant since most teachers will fall
into that category until micros are
more commonly used in schools.
More information on the scope of
the problems included at each
level would be useful.

This arithmetic practice pro-
gram uses educational aspects of
the microcomputer intelligently.
The motivation of the arcade
game format is harnessed. It is a
drill and practice package, not a
teaching one. As a drill and prac-
tice package it is more imaginative
and lively than most, and would
be useful at all levels of the

MULTIPIjOY

(Apple Arithmetic Software) by Paul Coletta $36.95 N.Z.

Preniice-Hall Inc Publication

While first and foremost a novel Educational drill tool. MULTIPLOY. U so much fun to

play thatyoushouldn'tbesurprlsedlili starts attracting people a way from video arcades.

Available a t all leading Booksellers, Computer Stores and through
BITS & BYTES Computer Book Clab.

Ditf, WHITEHALL BOOKS.

11

SOFTUmRC

primary or intermediate school.
The harshest critics are the con-
sumers, so I tried "Multiploy" on
my two 13-year-olds and 10 and
nine-year-old friends. It emerged
with flying colours.

Games for
the VIC

VlC-20 Games. Topes 1 and 2
James Electronics Ltd, Box 527,
Thames. $15 each. Reviewed by
AJ. Petre

With three good games a tape,
the James tapes are good value.
They also make excellent use of
graphics and of colour — too
many programs these days have
badly-chosen colours that do not
contrast. The result is illegible
lettering and invisible games
symbols.

TAPE 1 has "Snako" "Maths
Game", and "Ball in Bucket".
The first two need memory
expansion which should be
ehown more obviously on the
packaging. "Snake" is similar to
the caterpillar-style of game -
your snake (which will screen-
wrap) gets longer as it gobbles
mice. After a certain time mice
turn into gravestones, and if your
snake bites them, or itself, it
dies. Good sound, quite
addictive.

"Maths sets the task of
making mathematical expressions
of varying difficult equate to an
object number — a timed game
against the VIC. Good stuff for
making maths fun tor the kids,
and hard enough in its upper
skill-rates to keep even the
whizz-kids guessing. A good
mind stretcher.

"Ball in Bucket" is a simple
but good-fun dexte'ity game, in
which the player uses specific
symbols to bounce a ball into
containers.

TAPE 2 needs no expansion,
and has "Formula 1",
"Concentration," and "Line
Game". Two of these are for
two players — something we
need more of in computer
games.

"Formula 1 " is a fairly typical
race game, with good graphics
and colour, but only average
sound. You have to get around
the track without running or
spinning off, wearing out brakes
and tyres. The car is hard to see
at times which leads to
frustration and crashes. That
apart, quite a good axample of
its type, but less gripping than
some.

"Concentration" s simple, but
addictive. Two players seek
mystery symbols under the
letters on the screen, the aim
being to pair them up. It needs a
good player memory and good
attention — with good colour
and graphics, it's a winner.

SEND ME FOR MORE INFORMATION
OR TO ORDER:

Check-Point Computers Ltd
Private Bag, Tawa, Wellington
Phone: 326-999

1 8 K Microbes

S329

Rotail

32 K Microtoee

$990

Petaii

64 K Microtoee

SI 350

Retail

Single disk drive

Si 509

Retail

G*e?n screen tncoiiors

Synao

$299

Retail

Zenith

$349

Retail

Sanyo

$388

Retail

Education prices on application

information

LI

Order

U

I I

Prmieis

□

Screens

Li

Irak Drives

D

Disks

II

Sofuvare

LI

r«A«

ADOKSS

PW.V-"

"Line Game" is a simplified
version of the "Snake" or
caterpillar game — steer two
lines (one player each) into or
away from collision. Simple but
fun.

One point: "Formula 1" and
"Concentration)" have good
written instructions on the
leaflet, but none in the program.
A bad idea, I think. We all -end up
losing those little bits of paper.
then it's hell working out which
keys to use.

My rating for both tapes:

Loading and instructions:

Good.

Colour and graphics:

Very good

Value: Very good.

Player interest: Good to high.

A final point: these are streets
ahead of many imported
games. . . bet they'd sell
elsewhere. Governments, please
note.

l€TT€RS

Taxing the
computer

Sirs — Many thanks for a very
informative article on duty and
sales tax on software etc
(February '83 issue). As I write
this, I still await an answer to an
enquiry from the custom house in
Wellington. Perhaps, the com-
puter they use can' t or is st ill corn-
put ing the variety of tariffs
available to the department.

It is a pity I didrVt receive this
issue until the day of "media for
data processing equipment" or
they may have had this jumble of
words.

Once again, thank you and keep
up your informative reporting.

i. Mcdonald (Taupo).

It's less hassle
regularly

Having difficulty getting your
copy of "Bits & Bytes" regularly?
We suggest that you become a
subscriber. If you prefer to buy from
your bookstore or computer shop
place a regular order. This will help
ensure you always get a copy.

12

COMMODORE VIC 20
HOME COMPUTER-
ONE OF THE FAMILY!

World renowned VIC 20 - Commodore's bfftiart home computer « ai your
dealer's today! Ifs a larrvly machine - wth something for everyone . . . piay the
best video games available ... or teach yourself a language . . . write your own
programmes . . . even use it to budget or that new car! (And that's just a tiny
sample of what it can do!)
VIC 20 plugs straight Into your television set and comes complete with

• cotour ana souna • easy to learn BASIC anguage

• full size typewriter keyboard • easy to follow instruction manual

• graphics capability • full service and support

Take a look for yourself! The affordable Commodore VIC 20 e at your dealer's
today.

COMPUTER

13

home
computers

FOR YOUR

Sinclair ZX 81

Atari III

Commodore
Vic. 20

WE SUPPL V

* Hardware
» Recorders

* Printers

■ All Accessories

* Programmers Aids

* Software

* Handbooks

» Learners Aids

ALL DISPLAYED &

DEMONSTATED

Mail Orders Welcome

BANKCARD - VISA ■ CASH PRICES

K'RD

Video &
Computer

GRAPHICS

wwtaw i w i i w inii

i-.v'tt'it.*-/;* wtY* ■—■>-.■■■;■■■'■"■ -

End of the series

Computer graphics is now recognised as a major form of
computer addiction. A great deal of thought goes into deciding just
what a particular microcomputer will offer you for graphics ....
and a good deal more thought goes into designing tempting add-on
devices that you can buy at a later date. Such devices can help
you enormously in creating, displaying or interacting with graphics.
Some are cheap and some are expansive.

This last article in this series outlines some of the clip-on
graphics devices available on small computers. Basically such
devices can perform one or more of four functions. They can help
you create graohics more easily; they can help you display better
graphics and fnally they can help you process graphics more
effectively.

The clip-on path to
better graphics

65 PITT St.. AUCKLAND
Ph. 399 655

By PIP FORER

The most common graphics
add-on that can be found is the
paddle, often called the games
paddle- The Apple II at one time
came complete with a pair. Today
many people purchase them at an
early stage for an easy entry into
the world of computer games. The
paddle is usually a very simple
analogue device with a rotating
knob (connected to a
potentiometer) and a simple
on/off fire button. It relies on the

user's software for interaction

with the screen.

All the knob on the paddle does
is return a value in a certain range
(typically to 2551 which is
determined by the position of the
potentiometer. Statements in
BASIC or machine code translate
this value into a screen position
for drawing. Ttie user's eye then
appreciates this position on the
screen and adjusts the paddle
appropriately to affect the image
he Is getting. A single paddle is
usually used to allow the user to
control an object moving in one
direction, say [he laser turret in
Space Invaders. Two paddles
allow control in two dimensions.

More seriously, paddles are
often used in screen creation
utilities; for instance, to position a
cursor for the start of a label or for
locating a shape to be drawn.

A more sophisticated version of
the paddle is a type oi joystick
where movement of a joystick can
capture two potentiometer values
at once, one for X and one for Y
co-ordinates. The principle is
identical to having two paddles
but is made mechanically easier
for a human hand to cope with.
Musi Apple juyslicky are of ihis
type.

A second type of joystick is one
where a direction rather than a
position is sensed. This is typical
of Atari joysticks, the most
publicised of which is "Le Stick",
a free-standing column in which
direction is sensed from the
simple angle of the hand holding
it. Joysticks such as these return

codes corresponding to directions

of tilt (up, down, left, left and up
etc), usually returning nine
possible states. These correspond
to stationary and the eight sectors
of the compass <N, NE, E, SE, and
so on). Again the link to a program
consists of sensing the codes
returned by the joystick and acting
accordingly, In the case of
controlling the movement of a
shape on the graphics screen you
would need to check the joystick
response. If it was "move up and
left" then the X and Y values of
whatever you were drawing to the
screen would have to be adjusted
to do this.

The main operational difference
between the two types is that the
latter sort requires you to check
that your object stays on the

14

GRAPHICS

screen while the former ones can
be scaled to ensure that the
screen boundaries are always
conformed to.

Joysticks and paddles come in
various qualities (in terms of both
ruggedness and purity of
response) and are fairly cheap.
Other means of screen interaction
are more expensive. The most
popular is the light pen. Light pens
can be used to simply point at a
display screen so that the
computer records where the pen
is pointing. This is a bit more
direct than piloting a cursor
around with paddles. It differs
from paddles and joysticks by also
involving the screen directly. Most
decent light pens sense the
location of the pen by very
sensitive timing. The screen on a
monitor is refreshed regularly by
an electron beam and a sensor in
cheap light pens actually picks up
the passage of the refresh beam
over the screen. By comparing the
time at which this is sensed with
its knowledge of where the
refresh from the CRT should be at
that point in time it can calculate
tha X and Y positron nn (he
screen.

A word of caution. Because of
timing rates that differ American
light pens give peculiar results on
New Zealand machines using
standard monitors. This is
because the refresh rates vary in

certain countries. Also the poorer

pens only give a limited standard
of accuracy. Machines with built-

in monitors (such as most of the
Japanese machines) are able to
offer a far higher accuracy of
response than machines with ad-
hoc display units. Many 8-bit and
most 16-bit machines now offer a
light-pen port.

Finally there ere mice. A mouse
is a small, hand-held device which
can be moved by the hand over
any flat surface and translates its
own movements into a cursor
movement on the screen. The
mouse achieved a small fame with
Xerox, which used it for screen
interaction with a language
developed at its Palo Alto research
centre and called Smalltalk. It has
recently found wider publicity as
the main interactive device
employed by the new 32-btt Apple
Lisa computer. The computer
press have applauded it, Others
are imitating it but you will need
almost SUS1O.0O0 (and I suspect
some patience) 10 get within strike
of one just at this moment.

Capturing graphics

The second sort of peripheral is

aimed at capturing an existing
pattern on the computer. The two
most common clip-ons in this field
are bit pads (alias graphics tablets,
alias digiiisers) and video-
digitisers (alias frame grabbers).
These are typically quite
expensive peripherals but
extremely time saving.

Bit-pads are the most common
graphics peripheral after paddles.

The basic aim of these devices is

to allow the user to draw
indirectly on the screen through

using a hand-held pen or cross-
hair cursor. In general they are
used where an existing line-
drawing exists (say an outline of
New Zealand, a cartoon character
or a diagram) and the pen can
trace the design from a table top
and see it appear on the screen.
This has great attraction for the
99 per cent of computer users
with limited artistic talent and/or a
dislike of coding long strings of
co-ordinates. Using such a device
a complex shape, such as the

North Island, can be encoded to

the screen in a few minutes. The
information coming in from the
pen can also be used for other
tasks, such as calculating the area
of a shape by drawing around its
exterior. Geography students use
this regularly to calculate the area
of water catchments for instance.

The digitiser really is a great boon.

Unfortunately good ones are
expensive. If you digitise
information or shapes from large
Lands and Survey map sheets you
need both a large digitiser (able to
deal with 30 in. by 40 in. maps)
with very high accuracy (down to
1/100 in.) That is a five-figure
piece of equipment. The high
quality, smaller models weigh in
from S1500 upwards. These
usually consist of a flat tablet
perhaps 30 cm. square which is
connected to the computer by a
cable. A pen, also connected to
the computer, allows you to trace

r

The World's Most Powerful Small Computer . . .

Services Ltd

Available from A ^

A U7 WRISED DEALER FOR THE fJrtll ? Ih^TM! 1 MB-6890 MICRO

COMPUTER

fULL SOFTWARE RANGE AVAILABLE INCLUDING;

SMALL BVSINESS WORD PROCESSING MEDICAL DEVELOPMENT DATABASE CALCULATION GAMES

AUTHORISED DEALER ALSO FOR 2EDA COMPUTERS RUNNING CP/M COMPATIBLE SOFTWARE.

A CCESSORJES A VAILABLE: MAXELL FLOPPIES. SUNON COMPUTER FANS. BARE 5 'A ' FLOPPY DRIVES

SERVICING AND PROJECTS UNDERTAK EN.

AVEG

AVEC SERVICES LIMITED

Audio, Video, Electronics and Computer.

77 Victoria Street, P.O. Box 30S4, Christchurch. Telephone 795-619.

15

GRAPHICS

lines. The principle of operation
involves a fine mesh of wires
embedded in the tablet and more
fine timing. Essentially readings
from the wire mesh and the pen
tip are compared and the timing of
signals allows the position of the
pen tip to be computed.

These digitisers are accurate
but expensive. For many
microcomputers, whose owners
simply want to draw a picture on
the screen, the accuracy {and
cost) is unwarranted. A cheaper
set of digitisers exists using a
hinged arm to calculate position.
The hinges contain potentio-
meters (useful things that they
are) and as the hinge is opened or
dosed the angle (and setting) of
the potentiometer changes. From
this the position of the cross-hair
can be calculated and an image
traced from a table top to the
screen. Such digitisers need no
special table but still serve only a
limited size dictated by the length
of their arms. An American firm
(Penguin Software) has taken the
whole idea one step further by
having such a device that records

3-D ahepoa. It markets this with

software that displays such
shapes straight on the screen in
perspective •from any angle.

Far less common but an area of
increasing interest are the video
digitisers. These simply take the
input from a television camera and
convert this into a computer
graphics picture. The incoming
signal is broken down into a
particular grid of pixels (say 256
by 256) and stored in graphics
RAM just like any other picture.
From here you can superimpose
on it. clear bits out or modify it.
The capture is fast, sometimes
one-fiftieth of a second, and the
image often good. These devices
are the basis of "computer
photography" side-shows. Until
recently most cheap video
digitisers needed American
standard NTSC input so a New
Zealand user might need a special
camera for the task. British
manufacturers have begun to
produce systems based around
PAL which may offer a better
option for us. If you own a camera
already (a big it) video digitisers
are about the cost of a low-grade
bit pad.

Better graphics outputs

Graphics s essentially about
display, either hard copy or soft.

With soft (fcreen-basedl output
you can enhance your image by
essentially buying a better
monitor. The problem is that a law
of diminishing returns per dollar
spent sets in. Rough video is
cheap: you use the television. If
you ere dissatisfied with that a
proper colour monitor of the large-
volume production kind is
relatively cheap. If you go for a
basic RGB monitor it should cost
you less thar a home television. It
gives a calmer picture-
Incidentally, RGB stands for red,
green, blue, the three colours of
the individucl colour guns in the
set. RGB monitors are quite nice
since on some machines you can
interface them to the computer
throug h software-programmable
cards. These can be programmed
to set a background colour (set
one gun on all the time), delete a
primary colour (disable a gun) or
give coloured text on a machine
that does not have such a facility
inbuilt. However, most low-cost
monitors (and ceitainly all
televisions) have an upper limit to
the number of dots they can
resolve. On most it is under 300
points vertically. To improve on
this requires special circuitry
(which is higher cost and

produced ir smaller volumes).
These monitors employ a
technique called interlacing to
extend the resolution.

Thus the ACT Sinus gives 400
by 800 points monochrome while
the astonishing NEC Advanced
Personal Computer (not to be
confused wilh the PC8000I offers
800 by 640 colour on its built-in
monitor. Resolution above this
geis progressively more

expensive.

The othc peripheral is the
printer. Black and white graphic
printers are now commonplace.
The great growth recently has
been in colour printers. Although
exotic ink-jet ones exist in the
over $7000 price range, matrix-
dot printers offer colour at under
half this price. Their operation is
through a ribbon with at least
three horizontal coloured stripes in
it. To Create a Coloured screen
merely requires the printer to pass

,—..,.,._■

several times over with the
required mix of the primary
colours being struck. A screen
dump can take three minutes with
this but the effect can be striking
and cheap.

Putting punch in
the processing

The final graphics option is to
upgrade your processing power.
This can be done with one of
several options. The most
common is to firstly increase the
size of your memory. This just
allows more graphics screens to
be stored in the computer and
rapidly accessed. The next option
is to increase the speed of your
processor. This means (for those
machines for which it is available)
possibly a second processor that
is faster or one designed
specifically for processing
3-dimensional data bases. Such
add-ons are available for certain
machines. Finally you can do a bit
of both. It seems fair to end up
with the Apple II for an example of

thi? If ynu am constrained by

normal Apple graphics then

roughly SI 400 will get you a

board with RAM, a graphics
processor and 5 1 2 by 5 1 2 pictu re
resolution. That might be one way
to stick with a familiar system but
pursue new heights. You will have
to get a better monitor to cope
with it though.

The main lesson from this
discussion, and the preceding
articles, is the complexity of any
computer system, even a
microcomputer. The use of
graphics involves a whole
spectrum (acknowledgements to
Clive Sinclair) of techniques and
equipment and all must be well
matched. Good programs, fast
processors, friendly interaction,
good resolution are only part of
the whole. There is little point
having a great computer and a bad
monitor or a super program but a
weak processor. If you want to
get into this area, or are already in
it, mix and match intelligently to
build a system that fits your
budget, uses all its parts fully and
does the job you want done.

16

FARMING

— i^W.'UVWM W IHWMP i 1 ■' ' '

......... --.,., ,.u ..... ,,,,

Getting at the beast

by CHRIS McLEOD

Should you be using a computer
on your farm, and if so, in what
ways can you get access to a
computer.

There are three reasons for
farmers using computers on the
farm:

• If you are interested in
computers and their application
on farms, you may want to use
one as a hobby.

Any benefits you gain could be
considered a bonus; they are not
essential in fulfilling your aim. As
long as you get personal
satisfaction and can afford to use

the computer, then that is reason

enough.

• If you would like to improve
some aspect of your farming
operation, but not necessarily
improve your financial position
(eg, improve per head stock
performance).

A computer could help but you

must carefully evaluate the
software availablu lu wnsurw yuu
can use a computer to achieve
your aim. It would be best to seek
advice from someone familiar with
both farming and the computer

software available. Again, you
must be able to afford to use a

computer.

• If you warn to increase the
profit from the farm, a computer

could be used to help increase
income and/or decrease

expenditure.

This is the most likely reason,
and involves the most work in
evaluating software, costs and
benefits. Unless you have a good
knowledge of what software is
available, how you can use it, and
how you can put a dollar value on
the benefits, I strongly suggest
you seek advice from someone
who does.

Farmers who already own
computers, farm consultants, and
computer consultants would be
the best peop'e to talk to (but
remember some farm consultants
may not be familiar with
computers).

Idea — Before you commit
yourself, you must have an idea of
the annual cost of using the
computer (including any extra
time needed tc collect and enter
the required data), and the annual
financial benefits. Some costs and
benefits are quite obscure. For
example, what value do you give
to better manacement information

which will allow you to make
better decisions.

Now we will look at the various
ways you could get access to a

computer.

There are several ways you can
make use of a computer without
using it yourself. This could be
through farm consultants;

accountants; farm secretaries
working for consultants;
accountants etc; stock firms;
dairy companies; data bank
accounting service; and bureaus.

Several farm Consultants are
now using computers to process
information from clients' farms.
They can more easily derive useful
management information from
financial information such as you

would provide for your

accountant. They can use this to
advise their client, or give the
information to- the client for his
own use.

Because of the amount of work
involved in maintaining physical
records, most consultants would
restrict the use of their computers
to financial information. The
advantage of using a computer in
this fashion is that the cost is low,
and the consultants can provide a
great deal of information and help
which a computer could not.

Most accountants now use
computers to process their

FARMERS...

Save time and money!

Let Rural Computer Systems take you into the computer

age. At last farming programs are available in New
Zealand. Produced by farmers with the assistance of a
specialist farm accountant. Next time you are in
Christchurch contact Alister 8urbury at 160 Tuam St, or
phone 796-734, or Till in the coupon below. Sit behind a
microcomputer with Rural Programs and you'll find it hard
to tear yourself awayl

NZ distributer:

FARMPLAN

Authorised dealer:
APPLE
SORD

I I PlfiJSi tend me Rural

Computer Information.

■ □

■□
l_

Please send
aboBi Rural

Seminars

Please send
shoal Rural

NewslflMBt.

me details
Computer

me details

Computer

Name
Occupation

Address

FREEPOST RIO. 100

RURAL COMPUTER SYSTEMS

P.O. BOX 1136 CHRISTCHURCH

• Stock Recording
^Financial Planning
•Feed Budget ing

)• Word Processing
•Gross Murgtns
•Farm Diary

recording

17

FARMING

HmMHHfK

clients' data, but very few provide
anything more than a set of
accounts — useful for the tax
man, but not ideal for
management purposes. Much of
the information which could be
used for management decisions is
there, but not in a form which can
be easily interpreted.

At relatively little extra cost,
accountants could provide
farmers with a considerable
amount of information which
would be useful for management
purposes. We hope to see more of
this in future.

If farm secretaries were to carry
a computer around with them,
they could collect information far
more easily. This would have little
effect on you as a farmer. If
however, the farm secretary
carried a range of programs which
you may want to use, then a
bureau-type service could be
provided.

Stock firms use computers at
present to process their own and
farmers' data, but generally for
accounting purposes (the

rinmments. about accountants

would apply). We may soon see
changes in this area, however,
with stock firms offering bureau
type services. Dairy companies
are similar to the stock firms.

Data Bank runs a sophisticated
bureau service where you can use
a computer to carry out relatively
sophisticated financial analysis
and control. This system uses
coded checks indicating

categories of income and
expenditure as well as journal
entries which you make and send
in by post or deliver to a bank.

Once you have an

understanding of the system and
how to interpret the results, it can
be most use'ul. The cost is quite
reasonable.

Bureau - Bureau services
generally wcrk on a mail-in/mail-
out system where you enter the
appropriate information on a
coding sheet, then send it to the
bureau whera it is processed. The
results are mailed back to you.
The type of work and cost varies
considerably.

There are several ways you can
get access to a computer you can
use yourself. These are: full
ownership or lease; syndication
ownership (group ownership);
information system where you
use your own terminal; bureau
system where you use the
computer ycurself (basically hire).

Full c-wne-ship or lease has the
most flexibiity. You can do what
you want when you want. For a
dairy or stud farmer who make
almost constant use of the
computer, this is the only viable
alternative.

Often, a farmer with his own
computer may use other
computers, such as the bureau
service provided by Sheeplan. If
real-time data acquisition and
control is being considered, your
own computer is the only option.

Sharing ownership with others
may be possible if you do not need
a computer all the time. If you
were going to carry out financial
analysis and control work, with a
small amount of physical
recording, then this may be OK.

As in any syndication of
equipment, the rules of who can
use the computer and when,
should be clearly stated before

Computer now available
ex stock (while they last) - Only $1995

BBC

Wide range of games, plugs , leads in stock.

Authorized deafer for the

BBC computer and Acomsofl software.

Write for list to: COMPDTECH SYSTEMS,

PO Box 598S. Wellesley St. Auckland.

purchase, otherwise disagree-
ments and arguments could ruin
good friendships. Always keep
the syndication on a business, not
a personal basis.

Cheap - This could be a
relatively cheap method of getting
access to a computer for many
farmers. One way to establish a
"syndicate with minimum cost is to
follow the example set by a group
of farmers and a programmer in
Canterbury. They bought a
computer for the local high school
(saving the 40% sales tax) and
have use of it in the evenings; the
school uses it during the day.

Although I know of none
operating in New Zealand,
Information systems could have a
place in farming. An information
system can take many forms, but
in computing, this generally
means a large computer which
stores a great deal of information
on one or more subjects.

It is used like a library. By linking
up to the computer with a terminal
(keyboard and screen) or another
computer, you get access to
information in the large computer,
The best way to use such a
system would be to have your
own microcomputer for most of
your work, then when you want
to tap the information system, you
link your computer to the big
computer by telephone.

With a bureau system where
you use the bureau computer
yourself (instead o1 mailing the
information in), you could travel to
the bureau office or have a
terminal. With computer

equipment still relatively

expensive, this could be cheaper
than using your own computer,
although not quite as convenient.

If you are considering any of
these alternatives, you must still
carefully evaluate the costs and
benefits of eech system. If you do
not own your own computer, the
inconvenience of the other
alternatives must be valued as a
cost,

Naxt month, we will look at
what should] be considered when
determining the costs and
benefits of owning a computer.

18

BUSIN6SS

Final selection

By JOHN J, VARGO

Last month, we evaluated the
vendor proposals and reduced our
list to the most promising
candidates to supply our small
business system. We will now
look at the process of making the
final vendor selection and
implementing the chosen system.

Final selection - Having
chosen your short list of potential
system suppliers, you now need
to determine their ability to deliver
what they have promised. Your
selection was based on their
apparent ability to meet your
needs and the cost/effectiveness
of their system.

Final evaluation of vendor and
system capabilities will include:

• contacting current users for
their opinions and experiences
with the vendor and the system
you are planning to install.

• testing the system with
typical input from the proposed
user environment.

• evaluating documentation for
hardware anU software.

• appraising printed reports
and CRT displays for suitability of
format, quality and flexibility.

A System may appear to meet
all your needs and be very
effective on paper. But when it is
measured in its natural business
environment for ease of use,
vendor maintenance support etc,
it may be found wanting. You
need to discover before you buy if
the real capabilities match up to
the purported ones.

Contacting current users —

.To obtain names and addresses of
current users on your short list,
just ask your vendors. They
should be pleased to provide such
a list. But if they are hesitant, this
may be an indication of the quality
of service provided in the past.

A phone call may be convenient
for initial contact to determine the
user's willingness to provide such
information. The user's final
response however should be in
writing so that there are no
misunderstandings about your
questions, and to ensure clarity of
responses.

You may choose to prepare a
"user questionnaire" which

states the infoTnation you require
and may provide a scale for
response from 1 (very poor) to 5

{excellent}. Here are some
questions you may want to
include:

• How has vendor support
been in terms of hardware and
software maintenance?

• Has the hardware been as
reliable as you expected?

• Has technical and user
documentation been up to your
expectations?

• Have vendor training
sessions been satisfactory and
sufficient in scope to prepare your
employees for using the new
system?

• Have there been any other
areas you have found particularly
troublesome?

• Any areas you have been
particularly pleased about?

Based on the results oi the
questionnaire, you may want to
clarify certain points with the
vendor, or include certain items in
your contract.

Testing the proposed

Systems — Tasting the

proposed systems is the key
evaluation tool. A few days of
thorough testing at this stage can
save months of frustration later.
Tests should be performed using
samples of sctual transactions
from your business selected to
provide as wide a range of
circumstances as possible.
Transactions should include very
small and very large dollar
amounts, as well as erroneous
information of every variety.

The testing process will
determine the suitability of the
system to your working
environment, as well as testing its
reliability and error detecting
capabilities-
Documentation - Since the
system you choose will be used
for five years or more, it is
important the original

documentation is sufficient to
train future errployees as well as
provide an ongoing reference for
current users. There should be
user and technical manuals for
hardware and software

components.

All user manuals should be
clearly written and indexed so that

■™ „*,

a first-time user can read it and
not feel threatened. At the same
time, manuals should be complete
enough to be a useful reference to
the experienced systems

designer. Unfortunately, not every
manual may meet these
guidelines.

Appraisal of output - The

printed documents and reports
from the system, as well as the
screen layouts, should be
approved by the manager/users
and operator/users. If the people
who will be using the system are
not satisfied with the final output,
we may find the whole system
failing. We must always
remember the people in the
business are a key element in our
information system and the
success of the installation
depends on their enthusiastic
support.

Printed reports and screen
formats should be easy to follow
and as similar to the manual
system reports and forms as
possible. This requires flexibility in
the system and good
communication with users. This is
aleo on opportunity to evaluate
the quality of the printer proposed
for the system, and the quality
and stability of the CRT display.

The contract - By this time in
the evaluation process, it has
probably become apparent which
vendor is your top choice. A
contract should be drawn up to
formalise your choice and spell
out the responsibilities of both
parties. As a minimum the
contract should include:

• a specification of the hardware,
software and training to ba
provided by the vendor

• delivery dates and a program of
implementation, and related
payment schedule

• a specification of the
maintenance program for
software and hardware, and the
related costs

• any site preparation which
might be required for the
hardware.

These are minimal suggestions,
and it is recommended you
contact your solicitor for further
advice.

• Next month, John Vargo will
discuss the implementation of
a new system.

19

€DUCflTION

The mechanics of a
network

By NICK SMYTHE

This article focuses on a few of

the major questions and evaluation

issues surrounding microcomputer
networks. To do 1his we will refer to
several networking systems

available for the microcomputer
systems that have attracted most
interest: the Apply, Poly and BBC
Microcomputer. At present the

comments are largely secondhand
but perhaps at a later date we can
return to report on some "hands-
on" experience.

1 1s a network cost-effective?

The first part of this issue
depends on how many stations you
want to have and what sort o1 disfcs
and printers you want. Basically the
more computers the bettqr the
economics since for each station
you save on a disk and printer. You

can use that money either to get
better disks or printers or to buy
more computeis. Nothing is this
simple though so go to 3 to see at
least one caveat on this comment.
2 Will it lose my flexibility with
machines?

Usually no. Mjost networks enable
you to plug machines on or off with
little trouble . Tha machines you take
off are as autonomous as the
equipment you have. If you have
some small spare disk drives then
you can take any machine away and
use it as an independent micro

wherever you want. Later on you
can plug it back in. The real
question here is whether the extra
disk drive is available. An alternative
to full detachment is linking a

microcomputer in to the network

cable at another point. However.

there are limits on how far a

network cable can stretch without

extra equipment.

3 Can I add any number of

computers on?

In theory some networks have the
capability to recognise a large
number of machines. Some of the
Apple systems and Econet offer 255
stations for instance. This is a little
spurious since as you add machines
a nasty phenomenon called
system degradation sets in.
Essentially this is a microelectronic
traffic snarl-up.

Each user is fine while he is using
his own processor but whenever he
uses the network to share things he

has to compete with other users.

Once you get into large numbers of

users this competition can slow

things down a lot. The number you

can sustain depends on your use of

the system. If your use is disk or

printer intensive the number will be

be lower than if most of the work is

done by independent machines.

One way of looking at a network is

that you want users to get a fast

response time. Slow response, say

to a disk load, may indicate either

slow disks or slow transfer along the

wires or excessive queues. The last

category is the real killer and can

occur with surprisingly few users

in some cases.

• * 16 BIT PERSONAL COMPUTERS

sinus i " the way t ° grow

Up to 896K RAM
New 16 Bit Software
More languages
Communications
Notional support

128H Standard
WordStar, Micro Modeller

BASIC 86, C BASIC,
COBOLS, Pascals, FORTfiflN

Two RS232 Ports,

Parallel and I6€€ 48
fill Standard

Sirius the Number One Choice in business computers

Dealer enquiries welcomed

Write to BARSON COMPUTERS, P.O. Box 36-045
AUCKLAND

^a ^ ttg/\mf Disthbu ted throughout Australia and New Zealand by:

BAHbHM Melbourne: U Nicholson St., Abbota'trd, Vic., 3067. Tel: 41 9 3033
(^TVWTfeTO Sydney: 331 Pacific Hwy„ Crows Nest, N.S.W., 2065, Tel: 436 2764
^ywUJjfyuiF^ife; Auckland: 132 HunaiMreRd-Jakapuna. P.O. Box 36-045, Auckland

20

I need to know more about

the Sirius

NAME

POSITION

COMPANY

-.,..-,-. B

BITS . . e

N€LU ZEALAND'S

P€RSONfil COMPUTER MAGRZIN6

. BVTE3 .

The BITS 6 BYTES Computer

Bmk Club

Specials "for bonus-points
holders begin in the May
edition of "Bits & Bytes'

You've got a new ZX81? Then here's
the book to go with it!

Douglas Hergert's Your Timex Sinclair 1000
and ZX81 starts with the real fundamentals,
such as how to connect the machine to the
TV set and a cassette recorder. It takes you

through home to write programs for graphics,
calculations, games, and more. It introduces
VOU 10 BASIC.

The book also has ready-io-run programs
including how to turn your ZX81 into a super
calculator; how to make bar graphs to help
you calculate home finances, and how to
draw pictures on your TV screen.
This is really value buying at our cut price of
$11.85. This is 65c less than normal retail,
and you ate credited with a bonus point
which can be used to buy the great bonus-
point-only specials coming up later in the
year.

Get your order in now. Use the coupon on the
next page.

Just look at these prices!

You get a special credit in

addition! And they come

right to your home by mail

(We don't even charge for

postage or packing).

How it works —

Once you've bought a book, you're in the club. So just pick out the books you want, fill in the coupon on
the next page and post it in.

What you get —

We are offering savings on the cash you pay for each book PLUS we give credit bonus points on each
purchase. These are stored to your credit, and a nunber of times a year we will offer special great buys
for cash plus these points. These bargains will be available only to those with credit points. You get the
books post free!

This month's offer is only a beginning. We plan to widen the range ot titles until wc can offer one of the
world's best ranges of computer books.

Computer books to read and use

PROS'.

t cHirilKjIi

OcrI,wHowif Csiafcryar Computer Rodney 23Xs

An uaiy. itmetiariirtg o/idc to computet and peripheral
pTWOWiM- Speof'e advfc* fur the computet, lloppy flscs.
turd 4s« ( ihe Efl" rermiial, fie onsc. tape cms, itie
cxnpuKt mom, software :ro'o«urriB«iJt>Ofi. In 'he ivcrfls ol
"PwJofCompuCrg" iKs book is ", . cheap mufflncs".
Out pice $2275SaveS1.2Q
and earn two bonus points

Syt3x

Fieri CMps to Systems: An tiDoducWn io Miereotoeestor*

RodnSfZlks
A superb, fast-paced journey through the history of
mtcrosrocessors, the mcnoproMWi chip iiseH. its support
comperats, and iho dBSijn of an acaaf rncroconipuKr
system. You'll t«d out that mao processors were dVtfcped
Lvj:; "'!"■: i :'.ro'!!-ji :■:*. ■ "■■'■■.:■.-:'-".'.'" :"■>■ ■ '■:■•
becon* today's features and, mtst importantly, ho* c»v it *
:o understand rttiiioccipHHeij. Ths 6 what "Efefvwjff
becacocs" sad about ihs boob "One Bl &b Wtf
iniieducioiv »*b 10 the rujrdwre end ol tongs."

0uipciceS30.35Save51.60
aid earn three bonus points

£■.:..

a^plesuft BASIC A Teach-Yourself Inticdiulion

Barrie M. Peake
A. manual *pt New 2egiandeis- * one-book methcei q*
learning BASIC with the Apple. Instead orf picking
information from iv.o or three. ' 'You get quite a wide
view of the Apple svsiem wiili one book instead of
three Od four." wrlteh'icviewet Mike Wall in the
ftfli-ch issuo ol "Bits & Byies". Model answers.

; i ■:. ri'iJli'lli'U - - : r 1 1 . I:ji ..i.iv .- ... ..'Hi i.

J<jhn Mclndoe Our price $3.15 Sawo 50c

and earn abonuspo-int

Masisrinj Computer Pre granting p .t Gcsing

* EvnplHBi m" eonlJ»»o<I CSiiuc liar* Brlwnlof eolf ctutly ai
Iwe, or tot use n the cIssstOOT. In one boot. 0* essentia*
mfc-marjcr to learn e-uguitnwg. The language ;*»ght is
a*9C. Tha su*«, a fatm« ludu-er m natrojiing. funs j
c or Altar tetvcoE pompony.

Mrjir u Mr;!. ■-,-■ 'Ji:- nnct 59.-5 Savt 50c
Plus 1 bonus point

Get the order in today!

Pick out your books, fill in the coupon, and get it in the mail today.
Stocks are not unlimited, and the last in may have to wait.

FREE POST TO YOUR HOME,

plus BONUS POINTS!

GETTV5IK tHEMAIUOCAY

"o to.7, dl oul ihs coupon arid post it to:

t'f yen udJiesi <i n this way ro stamp is needed!
Pay «Hh order; Choque, money oiOjt cr- II in tho I

SIGNATURE: .,.

NAME: .. .. . -

AODPiSS'

rwposi 125

' Bits & B(t«~ Bw*$

Bw927

ChnsLcnjfch

irtfaid.'Vaacaid boxes

a

(zone!

I enclose Mvrreni lot the swve crder

HVinearol

; r;"^DDGi -

Card hotter s5nmt1.fr

Daie catdexpi'ES
Che^je Chewe

PWUl Cltkr ! 1

nut: .■ r .

PoscS nora LI

Please bcl theapprapiaieboias:

PteaH kt^ me, pat lies, the fotowng Woks :

Your Time* Sinclair 1000 and ZX8I (Merger!)

MiDKOfnpylta Pwign- and Troubleshooting

IZurnchaJil

Intedaco Prt>i*ris for the TUS BO tun lltaiigreni

Que". Keyboaidfig IAle*andor(

Production to T-Ebg llrman)
II From CNpi to Systems iZatai
_ InventcryM^flg^nBrntorSmallCcnip. (Atlirdonl .

Inroouctjori to TBS-30 Gtaphcs ilnmai*

Q Basic BASiC-Encftsh Odionary fMoororU

The Teft3e«fooi*s Gubs to VYotd PtocKitg

IChWianl

Ins.* Btsk Games ItAaieosianl

Don't, or How to Care fcr voi Ccmpulfii ii&H • . .

Aptfesoli BASIC <PeaMl .

Mastering Ccmjuier PtcgtammfiB iGo^itig'

Masking Ccmpt^ers tVirigh'J

Begeinbg BASIC IGoilmgi

BASK ptograTOnftgM tha BBC (Cryeri

_, StWwithBASlConinftVlCMiMowol

LeamngLGGQ sn ife Apple II (WcOwr)i«!
[_ AtaKiGam«»idft'aeti«insiK-oHe!al! ..
_ Basic Conput rig: ACompIeieCoiirsel-Oa'nlcrdl

_ WordStar made e«y *EnW

_ Vts*Calc;HomeardO'hceCofrfart»c(ilCasi!u*iU}
_ Dt&MveririrjFWrHIHogml

Total payment enctosect

Out

You

Prici

Si.*

Bonus PIS

11.85

.65

1

30.75

3.35

3

28-35

1.25

2

" 6.50

.46

1

15.«

.30

2

3035

160

3

24.65

135

2

1895

1.10

2

20.80

us

2

iess

1,03

2

25.18

1.32

2

22.75

1.20

2

9.45

.50

1

9.45

.50

1

9.45

50

1

11.35

.60

1

19-36

1.06

2

13.25

1.05

2

18.35

1.00

2

27.00

1.45

?

24.55

1.31

2

23.85

1.25

2

31.95

186

3

23.60

1.60

3

I

If- ..-.-

Machna(s) i n **Wi you a: e speciaB|r inteeesied

Put them on a shelf by the keyboard

tLUSIUJ V> V-ISTEE SKKIEf

Misianr-j Camputsta GGt »Viigrt

A s»J iKioduGticn lot me hi'JHad, nt 1« Me as i toil n a
ctmputio-wpreciilioitourK. Ccjbis ire liefl 1'W" the basis
of piahfrarnes. though such e«tiv*iy jpatraUxts as to
coinp io the posiib ifnes of lAJeot e< and an afcctronic money
jysteni 7«ll ivniieii n a concise. Brrtah Kyle, arc! well

Ourprics$9.fi5Save50c
Plus 1 bonus point

Maoiiil'an Master Saries

Interlace Projects tor the IRS-80 (Mod 1111-

RichardC.HaMgren
Fe* the user with some compute' experience. A
seties of easily tu't interface ixojKts avowing the
diservcrycl the computers capabilities. Mary fulfy
tested pracl cc hardware projects including review of
data transfer formats, aiwlon to-digital conversion
fcidoedbact wcjects. and controlling a video
playback device.

Spectrum Our price S23.25 You save St. 25
arid earn tw-o bonus points

Books help

you get the

most out of

your

computer.

Be in the club!

MICROCOMPUTER

DiSIGfJ AND
TROUBLESHOOTING

11 «!.,«*„• ™ fT, iui.

i*-j>^*>'

Microcomputer Design and TroubleshoQtinpj

Eugene M.ZumchaV
Considers every aspect ol microcomputer design
from the idea to mo working] system. Controller
functions, the de-relODrTwni system, read/write
timing, good hardwire design, the computer system,
hardware testing ai3 IrouWeshooting and Ihe three
basics of aoflwyc design: documentation.
philosophy, and technique.

Howard Sams Out price S30-75 You save

S3.35
and earn three credit points

QUICK

SH>t4J : .' T J ^»'Il ,'cB

Ifttfi,-.---- ^tfl

* ;

la

^51

Quick Keyboarong Vonnie Alex jnSor

Sua Micd "Competent Keyboarding in 6 Hows",
this book by New Zeslander Vonnie Alexander has a
unique method for tesch-yourself competent
keyboarding. A wail chart ol fmger positions is

included.

Methuen Qu price S6.50 You save 45c

and earn one bonu s point

Programming on the

BBC

Microcomputer

Basic Progmmmfng on the BBC Mtl .vdPmCryer

You've seen the machine on television, and this is
the Deck preaared to go with trns programme. It's
des«jned tc the new BBC, and; toachfls Iyb« to write
programs, draw end animate prunes and graphics in
full colour, design sound effects end program gomes.
Detailed glossary.

Cur pr.ee S 1 9.25 You save S 1 .05
and earn two bonus points

Atari Games and Recreations

Bv Hwb Kohl. Ted Kahn. and Lm Lindsay, P»oi*teJ hems of
preprogrammed g&nti to tfav Bu it ateo gives irrtt<ucton
readers need to improve on these games and create mote
complex and chaHengnj games of their o*n. how to loll
fortunes, com-ow sonos, guss rtfOJ es. dc A'ord n jkIk. and
anrnate cartaon ctiiractcis on Ihe Atari.

n Oufp.'ice&27.0OYousaveS1.45

and earn 2 bonus points

Buy now! These
are current
prices only

BITS. .&. .

, BVTE3

htrooUction 10 TRS-80 Graphics Oon, Inman

3no *oi on ihe 80 users' A complete introduction ia Ihe basics
dI graphics ptograrrnrg on tHc TR3BO, uiMg dctens ol
B.urote. ti bejm «ith the ircol beM ccrcepn of foe
drawn; ard teads to geomtnvic shapes, movrg figure
nrimatori and other note advanced topics

rjiliitiiurrt Press Our price i 18."95. Save S 1 . 10

and earn two bonus points

The Tenderioct's Cutfe to Wind Processing Barbara Cbrijrn

Wfisi do I n«d in tfe «av c( eojcfxiffoif Wil a word proosK*
oe o( use 10 rrW These are just s few o* the aestxrj rm
oool win answer.

tttthrurn Press Out priceS18.95.Siv*$1

and earn Ico bono po ints

Yot» Tlmex Sinclair lOOQandZXBl DcuglasHstgei
For Sinclair users: Takes you from the very beginning
and explains in simple, everyday language how 10
use your ZX81 to its fuiesi capafcAties. Haw to
cwuieci your TV 3nd cassette recorder and make
them work togeiher. Giving cc-nfrWW$. writing youf
own programs lc gravies, calculations, gomes, wind
rr.ore. Ready ic-iun programs include *
supercaiculaior: bar graphs for homo budgeting;
dra iviog pictures on the TV screen. A good boo* '0'
the new use*.

Svbex Our arlce $ 11 .85 You save 65c

and earn a bonus point

Ins * B ji»: Garres Richard Matecsisn

A Sua fltrfldiiMofi for artyem bojmKng progianming Tho
author has chosen the median of fames to reach readers now
;, r .. ■ ■■■ ■ ':: -'-;•■ EASK WC, rmfl. - -' putei
games art deurbed in detail the* eaplsned and analysed to
ilistrat* ho* the games were developed- flute. skjOTthns,
and coding dfferaoces from the TB-80 . Apple ". and PET are
atornctntd

Sybex Oorp-keW5.18SaveSl.32

a rti earn two bonus- points

Base Computnp.* A Complete Course TmCrjA*wd

From McGraw Hi) (Canada). Provides a broad-rased
introduction to computer science aid data processr^. utablc
for a variety of levels in high Knots, trove-nines c* industry
Bwnswiftojfi'r^ssutKaWrjiissCtmpoierHVnwoDd
Comioule's Come From' Gives deWed coverage ot computer
languages, rxog/arnmino. pfogrsn siructuie. logic, testing.
dccumentaWfl and program mainsyance.

McGrawhSI OurpiiceS24.6&Save S1.31

and earn two bonus points

Wo* dStar Mfxle Eaay Wal t*r f l!ln

In II euv lessons, trJs rtarwltor* demonstrates «■ Ihe
pOAemjl IwH*es o' the MicroPro WordStar system, lessons
cover everything I torn toad'ng. using the unique prinung, text
msupdatiw. and forming funs iors. Spiral botnd. il is ideul
to use wftta worWg at itte terrraaL

OibL."'; 0urphceS23.85YoiJsaveSl.25

and earn two bonus points

VisiCale: Home and Office Companion David dsflewu, |
hovirjgr; extensive cowraga d the pcpuSr VisCalc prop'sn,
and can do used by the novice and ewer; altce Fix Ihe novte.
n oilers 40 modeS that can be used immcdaio-Y (or pcrieml
and business applcatcos. For iraB-pflnhtisa source of nw
ideas and techniqies.

Models created with Apple 3.2 vers ion, bul will perlo'ir |usfai
*eli onriTtacheies with other versions.

OurpweS31.98SawSl.65
and earn those bonus points

Oscovb I Oil H: Learning and

Programming dhe FORTH Language rhsm Hegan

Wether you aie a Begone* seeing infomwiior on [hit mutti-
loceied programming language or a se'Qut programmer
.ilrtidy nsng f CR TH itiis tet* & a refeience tre; shx/d luit be
a.erlosked. Deuirtv FOflTH syn:a*.specifical'. jppKahlf ic
both FORTH 79 and FICFORTH.

Our puce $29.30 You save S 1 60
and earn thr ee bonus points.

learning LOGO in the Apple II ydOaugiit. « i>

lOGO'i a Piaget-oased way hto cmw m * muh -purpose
langunrje. rlcn lechftcal, learnhg by doing.

Prent. ce-Hall (Aus tralia! Out wkG S 1 8.05

You save $1,00
and earn two bonus poims.

r

POST YOUR SUBSCRIPTION TODAY!!

1

Please answer the following questions:

My interest is:

Farming

Education

Compoti'iQos

Bucinoee

Professional

Hobby use

General news
Adult S8 LI School 56 I School name Programs

Beginner
fo " n My field is:

Professional (medical,
PAYMENT:

NAME: ■«.

ADDRESS.

ZONE:

I unclose payment for one year's subscription to BITS & BYTES

VisacA'd
flnnkcatd

~TT

Curd Holder Signalu re

D ate Card Expires

Cheque Cheque Mo ...

Postal order Postal note C

accoun

ing old

Business

i

Education llocturer. teacher ate)

i

Consumer ihob-byisietcl

IJ

Farming

Student

Other

Do you use a microcomputer Ye

/No

II yes , wh ich brand

BACK COPIES

Please send me the following back issues at S1 e.ich plus 50c
postage and packaging each.

Issue Nols): _ .

Number of Copies:,

L

{Pfaase send payment with order. Note; no more copies of
Issue No, J or 2 are available and other stocks are limited)

J

No stamp is required

if you write this

address on your

envelope

Freepost No. 125

BITS 8c BYTES

P.O. Box 827

Christchurch.

EDUCATION

M i"«f«^ W»l" i l H 'M —l»l

A Will I need expensive peripherals?

This again depends on your
requirements. Networks become
unattractive when they stow right
down. Although the worst culprit is
user competition, clearly better
peripherals can ease this a lot. Hard
disks, lor instance, can perform at
an average of 10 times the speed of
floppy disks and thai can clear a lot
of queued jobs quite speedily.

The disk drive is particularly
important if you solve your printer
demand problems by saving printing
requests temporarily to disk. The
currently cheaper 5 V* in (loopy
drives arc slow and have a small
capacity. The spooling can run out
of disk storage room. Most
common 5in drives are in the 100-
180 kilobytes range. Recent ones
get to 400K. The 8in floppy is faster
and larger. Best of all is the hard
disk which has access times
typically an order lower than any
floppy and stores from 5 megabytes
(million bytesl upward. Hard disks
seem made for networks.
Furthermore cost competition
overseas is driving the price down
very fast, A hgrd disk with 5

megabytes should be available for
under $5000 (educational price) in
1983. In fact ihe Fanasonic 3001 16
bit computer now marketed here is

already rumoured to be more than

shaving that threshold.

While we are on hard disks it is
worth noting thai the sort schools
can afford do not have changeable
platters as a floppy drive does. The
disk is sealed in its container. The
corollary of this is that you need a
back-up system tc hold your files in
case the hard disk crashes. This
may be a tape or a floppy drive or
both. Formac Marketing in
Palmersion North is working on an
interface to permi: back-up storage
to a videotape recorder and this may
be a cheap possibility. The Corvtis
system for the Apple has a similar
facility. Running a hard disk means
more thought is given to a lot of
matters regarding file security and
who has what file space. This is
such that most networks would
want a floppy driv? and a hard disk
drive just for user flexibility.
5 What is a Megabaud netv/ork?

Another reason ;hat networks are
slow is that their transfer rate is

slow. The cable in a network allows
the transfer of data from various
devices attached to it. The speed of
this transfer is governed by the
cable and by the transmission and
reception ports in the computer and
peripheral. Some networks are slow
and some very fast. Some will meet
small needs and some major ones.
You can get an idea of what is
involved by considering the baud
rate of networks. A baud is the
transfer of one bit (an eighth of an
8- bit byte) a second. Network
transfer speeds in our range vary
between 9600 baud and 1 ,000.000
baud with several on 250.0QQ. This
Iranslates to 1200, 125,000 and
30,000 bytes a second or, in
practical terms, the transfer of an
8K file (say a Poly or Apple screen
image! would take 6 ■»• seconds,
1/15 second, or about 1/4 of a
second. As we noted there are other
overheads in timing. These may be
so significant as to dwarf transfer
times. A small floppy loading the 8K.
to the network would lake so long
loading on any network that the

Continued page 32

HX-20

PORTABLE COMPUTER

The little computer with big

performance

The HX-20 is a lull- function, portable computer.
Not a sophisticated calculator.

Its standard 16KB RAM expands up to 32K bytes, or
the 32KB ROM memory to 72 KB.

This remarkable portable computer also communicates
can connect RS-232C and serial interfaces to telephone c
and other peripherals.

The full-size ASCII keyboaid works just like a regular I
its complete with built-in printer, a LCD screen and music generation via a
piezo-electnc speaker. Full extended Microsoft BASIC Time and date (unctions.

Compared to ordinary computers, Epson HX-20 offers six big
advantages.

1. Small size 2. Built-in power source 3. Automatic function keys
4. Interfaced for peripherals 5. A Memory Saver 6. Costs less

MICROPROCESSOR DEVELOPMENTS LTD

24 Manukau Rd, Epsom Auckland 3. Ph (9) 540-128. Wellington Br.nth 1st Floor, World Trade Centre, Sturdee St.Ph W 851-917
DEALERS: Auckland; Calculator Centre. Ph 790-328. D.E. and J Goldfinch, Ph 483-342, Southern Software, Ph 778-525, Smwll
Systems, Ph 535-7389. Commu nicotians Specialists, Ph B76-W8. Twang*; Bay Computer* Ltd, Ph 83-633. New Plymouth;
Taranakl Micro Electronics, Ph 84-067. Palmersion North; Vrscoun! Electronics, Ph 86-696. Wellington; Office Requisites, Ph
721 -902. Dunedln; EcUpu Radio and Hobbles Ltd. Ph 778-1 02.

21

ATARI

V*ww^<™wwi(Wrtynw«™ l i™--*w'*»~-bV.w™*-

9 POKE 2*0:POKE 3,6:P0KE 9»2iP0KE 153S,7
e:POKE 1537,64:P0KE 153S,185:TRfiP 17060

1 itRAPHICS Ci:POKE 752,i:SETC0L0R 2,6, UP
OSITION OA&i? ," ESCPPE r)QZE":POSITI

ON 0,12:? ," G.C. ROBERTS"

2 POSITION 0*145? ," 1382"

3 FOR 1=1 TO 255 STEP 4: SOUND O,r,3,10:G
OSUB I10005MEXT I

5 FOR T=l TO l@:SETCOL0R 2,6, l: FOR D=l T
56: NEXT D: SETCOLOR 2,6,7: FOR 0=1 TO 50
:NEXT OiNEXr T:SOUNO 9,9,0,0

&W!8JSi- W 23!? " EfiSV! N0T fis E

3 FOR R=i TO 5: SOUND 0,TNT< RND< 1 >*256),1

0*10:MEXT R:NEXT T: SOUND 9,6,8,0

9 RET1 * «< (TflZE 1 >»

18 GRftPHICS 7+16:C0LOR 2:G0SUB 2096

« IPS! g*^ l5 *; '159,0,159,95,159,95,8,
95,6,95,0,58,0,46,6,5

13 DflTP 10,10/30,19,40,10,30,10,30,10,15

9, 10,^9, 10,29,59,29,90,20, 100,29, 159,2

0,30,39,49,30,50,30,70,30

H °ft T Q 86,30,90,39,120,30,150,30,46,40,

59,40,,0, 48, 109,48, 119,40,150,49,39,50,5

0,59,39,50, 1 99, 59, 1 19,59, 159,59

il 28 T ? ^^§'69,60,79,60,30,60,100,60,1
59,69,4,-'0,30,79,54,79,99,70, 100,79,156,
79*29,30,40*30,60,89,76,30

16 DPTfi 99,80,159,80,24,90,50,99,70,90,8
0,29,10,^0, 10,39,20, 10,20,60,20,30,20,93
,30,20,30,40,30,59,30,60

17 DATA 40,10,49,30,49,69,40,80,50,20,50
,50,50,64,50,94,60,30,60, 70,66,36,69,95,
70,2,70,10,70,40,79,50

18 DfiTfi 80,39,80,69,80,70,80,39,90,16,90
,38,30,50,90,79,96,74,96,95,160,30,109,4
0,110#30#110,40, 993,999

27 X=156:V=48

28 COLOR i:SETC0LOR 2,6,0

29 GOSUB 9090

62 If PI0ZE=1 THEN IF X<60 AND V<40 THEN
GOTO 27

S3 IF X<1 AND V<56 THEN GOTO 3600
64 GOSUB 7969

55 COLOR l: SOUND 6.6,e,8:PL0T :■:,'■': COLOF:
3: PLOT J, K: GOTO 28
I960 GOSUB 16009
1919 SOUND 6,64,10,8:GOTO 27

2990 READ X,Y:IF XOS98 THEN PLOT X,Y:RE
00 X,V:ORfiHT0 X,V:GOT0 2996

2919 RETURN

A-Mazing game for Atari users

A game for Atari users calf-eri
Escape Maze by G.C. Roberts of
Te Kuiti.

Requirernems: Atari 400/800;
1 6K memory; Basic Cartridg e; one
joystick.

Game Objoct: To escape through
all three mazes.

Difficulty: Intermediate.
Language: Basic.
Graphics & Sound: Yes-
Programme Line Analysis; —

Lines 1-8: Introduction. Add

the following lines if you want
SYSTEM RESET to restart the
Sarfte.

O POKE 2.0:POKE 3.6:POKE
9,2:P0KE 1536,76:POKE

1537.64:P0KE 1 538,185:TRAP
17000
17000 RUN

Lines 9-65: Ccmmands for first
maze. Gosub 2000 reads Data
lines (12-18) to draw maze.
Gosub 9000 t-9090) gives
joystick commands which control
the moving pixel. These
commands are same for mazes 2
& 3 also. Line 8000 specifically
gives time limit for all 3 mazes.
Line 62 tests x.y co-ordinates for
the invisible walls which if

ATARI AND EPSON SOFTWARE

Now available — N.Z. Designed Packages

•it Accounts Receivable

tV Hire Purchase

<? Stock Control

ir Television — Video tape rental packages etc

Custom programming available for your needs

Agents for Analog Software & Magazine for Atari users
Full suppliers of all Hardware and largest
Atari software agent in N.2.

Conto<t Kevin Butler

Communications Specialists Ltd., P.O. Box 15578, New Lynn. Auckland

New rental premises opsninq Rpnl at 557 Rrccttfe Henderson.

positive sends pixel back to start.
Line 63 tests to see if pixel is at
door of first maze. Line 64 with
Gosub 7000 tests for pixel hitting
wall (If positive Gosubs
1 000- 1 01 0); Gosub 1 6000
records number of wall hits- Line
65 draws pixel with colour 1 while
followed by colour 3 so as not to
leave a trail.

Lines 3000-4020: Graphics A
sound commands for escaping
first maze.

Lines 4090-5180; Commands
for second maze. Line 5157 is a
test for sending pixel through to
the third maze. Line 5159 with
Gosub 14000 tests for pixel
hitting wall. If positive Gosub
1 3000- 1 30 1 gives the graphics
& sound routine. If negative lines
14020-14030 randomly draw a
wall (14030) in maze at a low
probability rate (14-020). Gosub
1 5000 randomly places pixel
somewhere else in maze as a
result of being blasted & thrown
from wall.

Lines 5190-6090: Commands
for third maze. Line 6075 tests to
see if pixel is at door of third maze.
If positive lines 8000 to 8070 give
graphics & sound commands for
conclusion & replay option. Line
6080 with Gosub 7Q50 teM s for
pixel hitting wall. If positive sends
player back to start of first mazo.

22

3089 X=i:V=45:F0R T=l TO 3:F0R C=l TO 14

:SGUtC 0*64*C*C:SETCQLOR l,C*C:FOR D=l T

35: NEXT OrNEXT C

3885 FOR W=l TO 28:NEXT H:NEXT T

301S FOR C=8 TO 15 STEP 3:FOR 0=1 TO 10:

NEXT D:SETCOL0R 4,C,7

3920 FOR P=243 TO 31 STEP -7: FOR 0=1 TO

51NEXT Da SOUND 0,P,i0,9:NEXT P:NEXT C

3990 GRAPHICS 0:POKE 752,l:SETC0L0R 2,6,

4

4008 POSITION 0, IMPRINT ,,"C0NORATULATI

ONS!"

4865 PRINT **'YOU FOUND A HfiY AROUND THE
INVISIBLE MALLS i "

4020 SOUND 0,9,0, 0:FOR T=l TO 968: NEXT T

4890 REP1 * <« HAZE 2 >»

5090 HIT=0:nA2E=0:TinE=0:GRAPHICS 7+16:S

ETCOLOR 1,8*10:COLOR 2: GOSUB 2060

5100 DATA 0,0,159,0*159,0,159,95,159,95*

0,95>0,95*0,50*0*48#0,0*20*10*50, 10*60*1

9,150,10,1,20,30,20,40,20,66,20

5105 DATA 80,20,140,20,20*16,20,29,39,0,

30,10,10,30,38,30,90,30,100,30,44,30,50,

50

5110 DATA 36,30,60,30,110,30,140,30,10,4
0,50,46,110,40,150, 40, 28,58,56, 5-5, 88,58,
90,50,110,50,150.50,0,68,20,60
5120 DATA 24,60,60,60,100,60,140,60,20,7
9,40,70,50,78,76.70*80-79*148,78* 10,30,4
8, 80, 60, S0, 150,80

5130 DATS 10*40,10,56,20,50,20,95*30.20,
30,30,50,30,50,40,58,64,50,95,60,10,60,6
0*70,28*70, 70,S0>20.80.50
5140 DATA 80,60,80,70,90,34,90,66,100,30
,100,60,119,30,119,40,140,20,140,30,140,
60,148,70,150,10.150.40

5150 OATA 40,14,40.20,68,94,60,95.78,0,7
0,10,110,59,110,56,150,50,150,80,999.999

5155 X=156:V=48

5156 COLOR i:SETC0LOR 2*0*0

5157 IF X<50 ANO V<50 THEN SOTO 6088

5158 GOSUB 9090

5159 60SUB 14008

5180 COLOR l: SOUND 0,0*0,8:PLOT X,V:COLO
R 3JPL0T J*K":60T0 5156
5190 RE(1 * <« HAZE 3 >»

6908 TIITE=0: GRAPHICS 7+16:SETCOL0R 1.4,1

Q: COLOR 2:80SU8 2800

S#05 DATA 0,0, 159,0, 159,0, 159,95,159*95.

0,95,0,95,0,60,0.50,0,0

6810 DATA 10,10,50,10.60,10,90*10*100,10

,149, 10, 18*- 20, 68.20*80,20, 130,20, 140.28.

158,28,20,30,86,30,90.30, 1 19,30

6920 DATA 130*30*140*38,1,40*29,40,50*40

,140,48,20*50*30,50,54,59,130,50,10,60,2

0,60,58*60.96*60*100,60*110*60

6930 DATA 54,70,90,70,129,79,136,70,20,8

0,30,80,48,80.60,88,70,39,148,80,18,90,2

0,98*34,90*66,90,70,90,150,90

6940 DATA 18,10,10,30,18,50,10*86*20*40*
20,60,20,64,20,98,38,34,30,76,30,30,30,9
5,48,30.40*80,50.20,50,39

6058 DATA 50,40,50,76,50.30*50*30*60*1,6

8*10,70.14,70*30.70,64,70,95,80,10,80,20

,90,30,90,40,10.30,10,40

6860 DATA 180*14,100,30,108*44*100,70,11

3*60*110,30,120,28.129*36*120,60,120.70*

140,10,140*30.140,40,148,70

6870 DATA 130,50,130,60,150*20*150,58-15
0,60.150,90,999,999

6072 X=156:V=55

6074 COLOR i:SETC0L0R 2*8,8

6875 IF X<3 AND V<59 THEN GOTO 8080

6676 60SUB 9080

6830 60SUB 7059

6090 COLOR l: SOUND 0,8,9,0: PLOT X,V:C0L0

R 3: PLOT J. K: GOTO 6074

7809 LOCATE X.V,A:IF P=2 THEN SOTO 1890

7818 RETURN

7859 LOCATE X,V*A: IF A=2 THEN RESTORE :G

OTO 6

7355 RETURN

3800 X=i:V=55:F0R S=t TO 2: FOR 1=255 TO

1 STEP -4: SOUND 0*1,18*18

8005 SQSUB 10808: NEXT I

9019 SETCOLOR 2*INT(RND<1 >*16>,8:NEXT S:
FOR 1=255 TO 1 STEP -4:S0UND 0,1.8.10:60
SUB 11 008: NEXT I

3815 HAIT=18:F0R T=l TO 20: SOUND 0.INT<R
ND<1 >*256^.10,18:6OSUe 128&0:NEXT ?:SOUN

0,0.0.0

3020 WPIT=3:F0R 1=1 TO 255 STEP 4: SOUND

9,I,8*10:6OSUB 12980: NEXT I

8025 SOUND 0*0.0.9

8827 GRAPHICS 2=SETCOL0R 4.4,6

3828 POKE 789,12

8829 POKE 718.0

3830 ? "PRESS THE TRIGGER TO PLAY AGAIN

■

3840 FOR Y=l TO 598! IF STRI6<0>=0 THEN R
ESTORE :GOT0 6

8853 NEXT V: GRAPHICS 0:POKE 752,1
8060 POKE 709*12:POKE 710,0: POSITION 0,1
2:? ," THF END"

8870 GOTO 8070

9008 TirE=TIDE*-l:IF TIP1E=608 THEN GOTO 6
9810 J=X5K=Y!IF STICK( 0>=14 THEN V=V-1
9828 IF STICK<0>=6 THEN X=X+1 :Y=Y-1
9038 IF STICK<9>=13 THEN Y=Y+1
9840 IF STICK(9)=5 THEN Y=Y+i:X=X+l
3850 IF STICK<0>=9 THEN V=V+1:X=X-1
3068 IF STICK<9>=11 THEN X=X-1
9070 IF STICK<9.>=18 THEN V=V-1:X=X-1

9888 IF STICK<9>=7 THEN X=X+1
9890 RETURN

18000 FOR N=l TO 5:NEXT H:RETURN

11088 FOR H=l TO 5:tCXT M: RETURN

12080 FOR H=l TO HA IT: NEXT H: RETURN

13880 60SUB 15008

13905 FOR 1=1 TO 255 STEP 28:S0LN0 0.1.8

,18

13018 FOR T=l TO 15:P0KE 710*32+T:NEXT T

:NEXT I: SOUND 8.0,0.8

13912 GOSUB 16008

13915 RETURN

14980 LOCATE X,Y,A:IF A=2 THEN GOSUB 138

88

14020 IF RND<0>*290>1 THEN RETURN

14930 TX=X:TV=V: COLOR 2:G0SUB 15900:PLOT
X,V:G0SU8 15880: ORAHTO x,V:X=TX:Y=TV = RE

TURN

15000 X=INKRNtX0>*159>;Y=INT<RND<0>*95>

: RETURN

16088 HIT=HIT+l!lF HIT=4 THEN GOTO 6

16810 RETURN

17080 RUN

23

VIC

graphic
game™

ST*wDA«a

VIC

UKIEXA*MPEP

ExMiotei)

VIC

m 3k

By BRIAN BULLEN
When I first got my VtC, I
started at the front of the guide
and worked as fast as possible
through it. Every so often I'd)
come across something that
would) make me think "must
come back to that".

One of these was the section on
animating with Peeks and Pokes
(p61-65). It re-ntnded me of some of
the first television games which
appeared in New Zealand.

I want to show how their program
can be turned into a simple game,
and introduce a few features of the
VIC wa haven't yet looked at.

VIC
fix /amd ee

above

'$1^2*

O

1

(OS*

t
*4*

!«*♦

1

3K" fcAP

1

US&K

I

*o«

"£no/y

|

PoR

+e«

3 1 K

$ASIC

UStA

ne nosy

i

74f0

SCREEM

SC/tEEN

i

»;«

Erti

Ty

en

Pry

£*/«

NSiOKI

ext

AH tloM

S oriM

*4«8

Us£A
H«H6iiy

*ff(rt

337*7

Memory map of bottom 32K of three versions of
710 Memory Expansion.

I suggest you reread the section
in the guide. Be warned there is a
mistake on p62, line 6 - the words
row and column are interchanged.

Now for the game. To their
program, we will add a bat with
which to hit the ball, controlled by
the f 1 and f7 keys, a record of how
many times the ball gets past us,
and a timer to see how long we can
survive. Enter the program listed
below and run it.

As it stands at the moment, it's a
rather hard and unsatifactory game.
To get the bat to move fast enough,
you have to peck away at the keys
like a woodpecker, but we'll do
something about that later on. First
let's have a look at some of the
different parts of the program.

Interest

The first bit of interest is the

TIS = "000000" in line 20. This is
setting the VIC's built-in clock to
zero so that we can time how long
we play the game.

Lines 230 and 240 then use Tl$
and extract the minutes elapsed
using MID$(TI$,3,2), which picks
out two characters of Tl$ starting at
the third character In. Then the
seconds are extracted using
RIGHTS1TIS.2) which picks out the
two rightmost characters of Tl S.

This sort of technique can be
used whenever you want to time
something. You could even use it to
turn your VIC into the most
expensive digital clock on the
market.

The next lines of interest are 140-
160. Line 140 uses the GET
statement to see which, if any. key
has been pressed. In most
applications, the GET statement is
used in a loop which makes the
program wait until a key has been
pressed. 140 GET PS:IF PS =
"THEN 140 is the normal form for
this.

In our case, we most definitely
don't want the program to wait. Try
changing line 140 to that above and
you will see what I mean. Line 150
checks to see if the ft key has been
pressec.' and, if so, moves the bamp
the server Line 160 does likewise
for the f7 key and moves the bat
down, PY being the variable which
determines rh e bat position .

You could use any keys you
wished. You would just have to
chanqe the 133 and 136 CHH$

VIC

MHMMMMMMMMM itedta ge d j «i ii is wmmwo •ftMNmMafHmMMMm

values. -01 instance, if you wanted
to use U for up and D for down, the

values would be 85 and 68
respectively. (Appendix J in your
guidG has the values for all the keys).
Alternatively you could use a
statement such as IF PS = "U"
TH EN... This has the same effect.

Checks

Line 170 checks to see if the bat
has hit the ball (97 is the CHRS code
for the bat). If it has hit, it reverses
the ball's direction, makes the
appropriate noise and goes back to
line 60 to work out the ball's new
position wfthout putting the ball on
the screen.

Now to deal with that
"woodpecker" problem. The
easiest way is to change the two
control keys to N and Y. Then
change lines 150 and 160 to start IF
PEEK (37153) = 239 THEN... and IF
PEEK (37153) = 247. Now you
don't have to peek at the keys but
simply hold down the desired key.

This effect occurs because we ate
taking advantage of the VIC's polled

keyboard (that's another article in
itself}.

Make these changes and run the
program. The game is far more
playable, isn't it?

However, there is still one
problem to sort out. You should
have noticed thatwhen you finished
the game, it came up with the
normal questicn, "ANOTHER

GAME" and then a whole lot of Ns
and Ys.

Key

The key to what is going on here
lies in the fact there are exactly 10
Ns and Ys. This is because the VIC
has a keyboard buffer which stores
the keys as they are pressed and

Continued page 39

Program listing

10 PR I NT' 'IC LEAR)"

165

POKE 17680*21 * 22"PYI ( 97

20 POKE 36879. 10S:POKE36878. 15:71$

170

IFPEEKI7680-* X * 22"Y) -97THECJDX

-"MOW

- -DX:DY = -OY:POtfE36878.180i

30 X=t:Y-lO:DX=1:DY-l:PY= 10

GOTO60

40 POKE 17880 + X-4 22^1.81

\m

GOT040

£0 FORT - !TO10:NEXT

zoo

C-C-1

60 POKE(7680(X'-22 , Y),32:POKE(7680

?iu

Y INTIRN0<1P23I:X = 1:IFC *20

*2H-22 , PY>.32

THENPY- 10:RETURN

70 X = X + DX

vw

P0KE3W79,27:PMNT"KtfAfl,

80 1FX = OTHEND3U-DX:POKE363?6.220

0OWN.3RIGHTJGAME OVER"

90 IFXX1THENGOSUB2G0

■m

PRINT" YOU SURVIVED FOR "•

lCO Y-Y+DY

MIDS(Tt$.3.21

110 IFY-OORY = 23THEPJDY = -DY:POKE

740

PRINT"MINUTES & "; RIGHT* HIS,

36876.230

21;" SECONDS"

130 POKE36876.0

260

INPUT"ANOTHER GAME";RS

140 GETPS

m*

IFLEF7SlflS,l|-"Y"THENO0:

150 IFP$=CHR$(133>THENPY = PY 1:

GOTO10

IFPYOTHENPY -0

270

PRINT"GOODBYE FOB N0W;EN0

160 1FPS-CHR$n36)THENPY = PY*l :

READY

IFPY>2?THENPY = 22

The Portable
Business Computer

CONTACT YOUR LOCAL DEALER NOW!

$3815.00

This includes double density!

yVCifju5

2 Manukau Rd Epsom Auckland
Phone (09) 544-415, 504-7S9
y\ ^J) Siptcm* visit our showroom.

AUTHORISED N£W ZEALAND DISTRIBUTOR

OSBORNE DEALERS

COMPUTER WORLD LTO: Cnr Lome A Victoria Sts. Auckland

Ph31-394 POBOK967 Ms <^ fttfwii. Minagar.
FINANCIAL SYSTEMS LTD: 161 -163 JervosRd. Home Bay,

Auckland. Ph 789-068 or 789-069 (Specialists in financial

modelling). PO Box 46 068. Heme Bay. Or Mike Snowden.

Director.
MACH1NEHEAO COMPUTER CO: 9 Mormon St, Auckland

Ph 77 1-566. PO Box 47-0&3 Mr Warren Wil&Ort. D-erfor.
TECHNOLOGY RESOURCES LTD: 8 Thackeray Si.

Hamilton Pt> 393-801 . POBox4063. Mr Wally McKenzie.

Director
WAIKATO COMPUTER CENTRE LTD: 6 Pnnces St. MamJlon.

Ph 393-416. PO Box 1C94, Mr Bob Dean. Dwoctor.
THE COMPUTER SUITE LTD: 84 Efuora St. Rotorua. Ph 497-507.

PO Sox 1 858. Mr Stove Peacocke, Director
LAKELAND TV & STEREO: 43 HOfomatanQi &. TaupQ>. Ph 88-868.

PO BO* 892. Mr Harry Leusink. D-reckx.
TIMMS' BUSINESS EQUIPMENT LTD: Tennyson Sl ( Napier.

Ph 54-250. PO Box 308. Mr Nevlllo Bannister , Sales Exec.
CQMPUSAL6S SOFTWARE * HARDWARE LTO: 7$ G- u: r»e* St,

WeBrfllcn Ph 728-658. PO Box 11-819.

Mr Warren Cardno, Director.
EINSTEIN SCIENTIFIC LTD: 1 77 W*s St. WeDirigton.

Ph 85 1 -055. PO Box 27-1 38. Mr Raju Badianl. Manager.
SMALL BUSINESS SOFTWARE LTD: 2nd Floor IBIS House.

Ph 64-617. 183 Hereford Street, Chr-sfchurch. POBox 1013.

Mr Bruce Foufds. Managing Dxoctor.
ECLIPSE RADIO & COMPUTERS LTD: 134-136 Stuart St. Dunotiin

Ph 77 8-102 PO- Box £270. Mr Stuce McMillan, Manager.
LEADING EDGE COMPUTERS LTD: South City Mall. Ounedin

Ph 55-268.PO Box 2260. Mr George Orr 4 Mrs Elaine Orr .

LVectors

25

Panasonic

FUNCTIONAL SPECIFICATIONS

• Microprocessor

Model: MN180O (equivalent to 6802)
Clock frequency: 890KHz
System Reset Function

• Memory
BOM: 8K Bytes
RAM: I6K Bytes
Video RAM: 1K Bytes

• Keyboard

System: Sottwaie scanning

Keys; 5-shlft key mode with 45 keys, SHIFT key and CTRL key

• Display interlace

Screen size: 24 lines x32 characters

Characters: 64 characters witu 6x7 dot matrix

64 semi-graphic characters with 8x 8 dot matrix]
Characters & symbols specified by user: 32 characters with

SxBOotmairix
Attribute: Inverted display function
Composite video signal: with 75 ohms, W p-p or with
BF flip-Hop converter
•Cassette Interlace
System: FSK system 1.200Hz (space), 2,400Hz (mark)

Baud rate: 600 Bauds

• AC Adaptor
Input Voltage: AC 1 10V, 120V or 220V*10°/o, 50r60Hz:
Output Voltage: DC 17V. 7.8V and -8V
Power Consumption- 12.5V/

• BF Modutatoi

Panasonic *

just slightly ahead of our time

Pn!?

THE MICROCOMPUTER
ELECTRONIC COMPANY LTD

IN A5SOC<A1l-QN WITH WISHER A IWKFl LTD

27 GREAT SOUTH ROAD, NEWMARKET,
P.O. BOX 9224, AUCKLAND 1, NEW ZEALAND]

TELEPHONE (9) 504-774.

TRS80/SVST6M 80

•mnvmay »•*-■"»)-"'

Living with
accidents

By GORDON FINDLAY

In my job, and because corn-
puling has become my main in-
terest outside work as well. I see a
lot of software. Much of it is
pretty hard to work with.

This includes a lot of commer-
cial software - it is hard to love a
system in which an accidental
press of a particular key can
destroy all of the last two hours'
work. Vet this is just what hap-
pens with Apple Logo — hit
RESET (which is right next door to
RETURN, for heaven's sake) and
you are completely sunk.

And what about the programs
which die when you make a little
typing error?

A little programming can get
around these problems.

Here are soma techniques for
making your programs easier to
work with. The main thing is to
make input as painless as possi-
ble. This usually means avoiding
the INPUT statement, which is far
too inflexible for most purposes.

This first routine is pretty ob-
vious — it simply scans the
keyboard until a key is pressed,
then returns to where it was call-
ed, with ZXS containing the key
pressed:

10010 ZX$=IWKEYS: IF ZXS = "
"THEN 10010 ELSE RETURN

Notice there is noth ing at all bet -
ween the two quote marks — we
are comparing ZXS to the null
string, not a blan<.

Input given by ihe user of a pro-
gram should always be checked.
A program will usually crash if a
string is given rather than a
number. Using The INPUT state-
ment isn't all that helpful — here is
a subroutine you can use to input
one key, which must be a digit. If
a letter or other ciaracter is hit, it
is ignored. The thsory here is that
most typing errors occur by hitting
keys near the correct one; and let-
ters are often typed accidently in
numerical input.

10020 ZXS=INK=YS: IF (ZXS <*
"O") OR {ZXS- "9") THEN
10020 ELSE 2X=VAL (ZXS):
RETURN

In this case, the digit is returned
as the variable 2X. and as tha
string ZX$.

Now we can elaborate this idea
into the following subroutine,
which inputs a njmber which it
returns as ZZ. This can be used as
a subroutine: instead of usinp)
INKUr AS, use GOSUB 10030:
AS = ZZ.

In this subroutine, only digits,
the decimal point, and the ENTER
(or NEW LINE) key are acted on —
everything else is regarded as a
typing error, and ignored.

10030 CR$=CHR$03)

10040 2Z$=""

10050 ZXS=rNKEYS:|FZX$ = " '*

THEN 10050 ELSE IF ZX$ = CRS

THEN ZZ=VAL tZZ$): RETURN

10060 IF (ZX$*"9") OR (ZXS «

".") OR (2XS='V"ITHEN

10050 ELSE ZZ$=ZZ$+ZXS:
PRINTZX$;:G0TO 10050.

This subroutine works by filter-
ing out alt the unwanted
characters, and jumping the rest

together into a string. The VAL
function of Level II BASIC func-
tions quite happily for strings, in-
cluding decimal points — a point
(pardon the pun) which not alt the
books seem to be clear on.

Of course, this only accom-
modates positive input- The next
subroutine accepts a negative
sign as first character, allowing
negative values input. Again, the
subroutine returns ZZ;

10030 CRS=CHR${13)

10040 22$ = " "

10045 ZXS = INKEYS:IF

ZX$=" "THEN 10045 ELSE IF

ZX$="-"THEN

ZZS="-":PRINTZXS;:GOTO

10051 ELSE GOTO 10051

10050 ZXS=INKEYS: IF
ZXS="' r THEN 10050

10051 IF ZXS=CRS THEN
ZZ=VAL (ZZS)rRETURN

10060 IF (ZX$»'*9"J OR
1ZXS«'\") OR (ZX$ = *7"JTHEN
10050 ELSE

ZZ$=ZZS+ZX$:PRINTZXS;:
GOTO 10050

This looks clumsy, but isn't
really — it can keep up with fairly
fast typing. Don't use it io your
new word processor though.

Tricks such as this have other
applications too. The clumsy user
who hits shift-backspace will be
surprised to find all he has typed
disappear. A simple problem —
use a routine like those outlined to
filter out the keys which are not to
be acted on-

YES, YOU CAN AFFORD A PRINTER!

NOW AVAILABLE IN M.Z. — THE AMBER 2400 DOT MATRIX PRINTER
• Sei'dl a«0 Parallel tnpul • Full Qrapmctt capability — eacfKKMlryiMduiHyproeiainma&lp •
Conventional 35 pin "D" type P'ufl • 2* column pint on plain paper • Low cost pacer idOl
tolls only 70 contsefcuii) • This la not <i theimal oi spark discrta'go type primer.

S| ■ I i"'ac*Ci&le*m&y wi-wOoo' * jrmvrie heme
■ - Of- tQUMl

For orders or mo<o

information, phone or write to

THE GADGETS COMPANY

P.O. Box 52-081. Auckland.

Phone (09) 862-260

(SOLE N Z. AGENTS) DEALER ENOUfltES WELCOME

PRINTER

$395.00

NOW AVAILABLE
VIC 2) INTERFACE

$95.00

ALSO AVA1ABIF FROM K'RD VIDEO 4 COMPUIERS. 6b PUT S' AUCKI ftNQ l. PHONE 103] 399 65 S

27

TfiS80/SVST€M 80

Another help to the user is to
force correct input by giving the
proper format on the screen, and
ignoring anything that doesn't fit.
As an example, here is a
subroutine to inputs a date.

The format ../../.. is
displayed, and as characters are
input, they fill up the spaces. The
day, and month, figures are
checked for reasonableness as
soon as they are complete. The
disadvantage - single digit days
and months must be given a
leading zero. It isn't a lot more
work to program around this; you
need only check for a carriage
return, or arrow key or whatever
you choose to trigger a move to
the next field.

10 SCRN = 128 * where it all

happens.
20CLS

30FMT$=" . ./. ./.."
40 GOSUB 10000
50 END

55' - —

9997'

9998 ' date input subroutine.

9999*

10000 PRINT <gi SCRN,

FMTS;:PRINT@SCRN.*'";

print format and go back to

beginning of it.
10002 ZZ$=- ":GOSUB

10030:DAY =VAUZZ$)
10004 IF (DAY « O) AND <DAY «
32) THEN GOTO 10008 ' skip er-
ror message.

10006 PRINT @ SCRN+64.'*ER-

ROR: incorrect day. Press any key
to continue.": GOSUB 10040:
PRINT <& SCRN+64.

CHR$|31);:G0T0 10000
10008 PRINT @ SCR+3." "; '
move to month field
10010 ZZ$ = " ":GOSUB

1 0030: MTH = VALIZZS)
10012 IF (MTH - 1) AND {MTH -
13) THEN GOTO 10016 ' skip
error

10014 PRINT @ SCRN + 64, "ER-
ROR; incorrect rronth. Press any
key to continue.": GOSUB
10040: PRINT @ SCRN+64,
CHRS(31»;:G0TC 10008
10016 PRINT @ SCRN+6,
" ";:ZZ$=" ":G0SUB 10030
1 001 8 RETURN ' to main program
calling 10000

10019 ' next subroutine sets one
digit (only!) and adds to ZZ$

10020 ZXS=INKEY$: IF {ZX$ «
"0") OR <ZX$» "9") THEN
1O020 ELSE
ZZS=ZZS+ZXS:RETURN

10029 ' this subroutine sets two
digits, echos them.

10030 FOR 1=1 TO 2:GOSUB
10020:

PRINTZX$;:NEXT:RETURN
10040 IF INKEY$= " " THEN

10040 ELSE RETURN : pause until
key pressed.

Of course, if you want to pro-
cess or store the date, you need to
pick up the day, month end year
as they are input.

This sounds a lot of trouble, and
not very interesting. But it isn't
really, and the results are well
worthwhile. Besides, you need
only write the code once to have it
for use in any number of
programs.

This little demonstration looks
fairly good — and it will look even
better when you add a flashing
cursor to it!

COMPUTERS

are really nice to kids!
] (they like adults too ! )

the Computer Centre, you will find the best range of
easy-to-use home computers in Christchurch. Our friendly
knowledgeable staff can help you decide which computer
best suits voir needs. And after you have bought your
computer we are only a phone call away, if you have any
problems. You can buy a full colour home computer from

us for less than SI 000, and we ^^^

stock a wide range of programs ^ ^^l

priced from SI 5. Computer m [COMPUTER

Centre - for the ^CENTRE LTD

best in home computers. ^^ fc^^

cnr COLOMBO & ST ASAPH Streets
Christchurch HZ Ph 793-428

28

BOOKS

Sinclair
book a
good buy

"Your Timex Sinclair 1000 And
ZX81."

Published by Sybex Publications,
Author, Douglas Morgan Price
$12.50. Reviewed by Tony Lewis.

At first glance this book looks
like a rewrite of the ZX81 manual.
Further Inspection reveals that it is
a lot more. Used in conjunction
with the ZX81 manual it would be
a very good guide to the beginner
on the Timex 1000 or Sinclair
2X81.

There are five chapters and two
appendices. Chapter one, "The
Cast of Characters," goes
through the initial setting up of the
machine and what each pant does
and what your role is.

Chapter two, "The First Act:
Enter Your Program," deals wfth
the computer keyboard and the
BASIC language used,

Chapter three, "The Plot
Thickens; A Short, Graphic,
Course in BASIC," looks at the
graphics capabilities of the Timex
1000 and the commands needed
to use them.

Chapter four, "Take Five:
Numbers on Your Computer,"
explains how the ZX81 or Timex
1000 can be used as a calculator
and how to generate bar graphs.

Chapter five, "Words, Words.
Words: Strings and String
Functions on Your Computer,"
completes the book by explaining
the use of strings and how you
can "slice" them.
Programs are used throughout the
book to illustrate what is being
covered in each chapter.
Appendix: A gives a list of the
BASIC vocabulary and what each
word means.

Appedix B gives a list of error
codes used by the Timex 1000
and Sinclair 2X81.

Most programs in the book will
run on the Sinclair ZX81 but since
the Timex 10O0 has 2K of
memory instead of the IK of its
English counterparts, there are
some programs that require 2K.

In summary, in conjunction with
the Sinclair manual this book

could be very useful to the
beginner as ft covers some areas
that the manual overlooked. Value
for money it has *o be a good buy.

Useful
Pascal
work

"From BASIC to Pascal" by

Ronald W. Anderson, Pubfishgd

by TAB Books inc. 310 Pages.
$21,95. Reviewed by Gerrit
Bahlman.

If you are an exoerienced BASIC
programmer who needs to be
convinced that there is something
in the structured beast, Pascal,
then this book may be what you
are looking for. By no means is it a
beginners guide to Pascal. If offers
a solid introduction which
assumes a sophisticated

comprehension of programming
jargon and makes little concession
to the novice.

Notions such as the distinction
between value and variable
parameters oie not explained In a
simple way, uti ising examples
and diagrams — it is explained in a
textual fashion that would leave
the novice stranded.

The book provides a very good
comparative study between the
two languages by programs
presented in BASIC then Pascal,
with explanations of their
differences. The old much used

recursion example of "Factorials"
is presented as is a non-recursive
version of the same exercise.
While interesting, this is the only
example of recursion cited and)
once more fails to satisfy the need
for more appropriate examples of
this difficult concept. This is
particularly true of the
experienced BASIC programmer
who has developed a mental
attitude to non-recursive solution
of problems which make recursion
approaches difficult to grasp.
The most attractive feature of

Continued page 35

Inlereslcd in le.ivmg this world' Vvv*
iry Du ngcons & Dugom «\

If.ivi'lk-r

lunnris ATrolK

Chivalry & Soicciy

Thieves World

Arduin Grimoirc

6, many more

Onv ol dw",c role playing systems
mu'i hf* the key for you.

Send S.A.E. to* a booklist ffi

Wc cm help you! -_ SfiK,

cne-tvmriH.-O'Ui'.mf.-u.M-o f"w»"

|)hOOU> I ">!<■' illunti J»tl.\n pthMH: r*jr*/ jS,

I

Whitehall Books Limited

Distributors for:-

BASIC PROGRAMMING ON THE BBC
MICROCOMPUTER

Cryer and Cryer S2O.30
Prentice-Hall (UK) publication

This book is appearing in conjunction with ihe N.Z.T V ten-nan
series 'THE COMPUTER PROGRAMME" starting 2nd March.
(Wednesday) just before the 6.30 news.

Available from this magazine, computer stores and

booksellers.

29

SOftD

■aitMm. ii iit t mi ii wiw iw mm m iBMWuwiwHtiiHW

PIPS III update — memory file pages

By Peter Hyde

Over ihe past few months, a
number of SORD M23 users have
bought and are using PIPS-HI, the
latest release of SORD's Personal
Information Processing System. In
that time some discoveries have
been made which will make the
use of PIPS- III easier, and increase
the power of the system.

The first of these discoveries
relates to getting the full use of
the 128K of memory available in
the M23. When PlPS-lll is loaded,
most of this is occupied by the
PIPS program itself and the
memory work areas of PIPS which
you know as the Master Buffer,
Sub Buffer and Figure Buffer.

The disk drives provide the
permanent storage areas known
as the Master File and Sub File.
However, there is a temporary
storage area known as the
Memory File, which can hold three
PlPS-lll pages. This large storage
area in memory is useful when
you want to work with several
pages of data without having to
access the disk.

Transfer of the contents of
these pages to and from the
Master Buffer is almost
instantaneous. Thus you can save
a second or two by saving pages
in the Memory File instead of the
Master File or Sub File.

Note; Because the pages are
stored in Memory, their contents
will be lost if you turn off the
power. If you exit from PIPS, and
then Te-enter without first
powering off. the memory pages
(like the Master Buffer) will be
intact, except for the first one.

Now let's* find out how to
reference the three extra pages.
This is by m eans of the P (Put) and
G (Get) commands used for
saving and retrieving pages on
disk.

Just as the statement: P;1
saves the Master Buffer content in
Master File page one, so: P;C1
saves the Master. Buffer in the first
Memory File. The codes C2 and
C3 refer to the other two pages
available.

To retrieve the second page
enter. G;C2 and press RETURN.
Whatever is in that page will
instantly appear in the Master

30

Buffer on the display screen.

These memory pages cannot be
referenced by PlPS-lll commands
such as SORT, CS (Conditional
Search). CAL (Calculate). L (List
to Printer) or UPD (Update). These
commands, and a few others,
allow you to specify a range of
pages on which the command will
operate (e.g. L;S1,8 prints Sub-
Files one to eight inclusive).
However, you cannot specify
SORT:C3...orCS:C1.2...

The reason for this is that some
of these commands actually use
one or more of the Memory File
pages for their own operations.
For example, CS. UPD and CA use
the first few line* of C 1 for storing
the search conditions, SORT
sometimes uses C2. And C3 will
contain any automatic program
you are executing (or have
recently finisher executing).

This imposes a limitation on
your use of the Memory File. Treat
the pages as a purely temporary
storage area (like the Sub-Buffer!
and save them on disk before you
execute a conmand which may
use them. Above all, DON'T use
C3 in an automatic program!
NOTE TO PIPS-II USERS: Yes. you
have Memory File pages as well —
7 of theml They are accessed by
the commands. "PCF" and
"GCF", and do not require "C"
prefixes on the page number, e.g.
PCF;6.

Now that yoj have discovered
the memory Files, there is one
immediate application for them.

Many users lave asked: "Is it
possible to have PIPS remember
my commands as I type them in so
that I do not have to re-type them
when creating an automatic
program?"

Short answsr: Yes. Memory
page C3 can oe used to log all
your commands as you type
them. You can then edit them
(using the ED command) and
finally register your new
Automatic Program.

Use the following command
sequence:

0; TITLE This create s a blank
page in the Master
Buffer, with a title

of your choice.
<ESC> Press<ESC>key to

P;C3

SET;
LOG=ON

KIWVHmRM^MOTfifdHVMSMflyVWi^P

end the

command.
Save the blank
page in C3.

Activate logging of
your commands.

issue any

commands

you wish to

use in your

programs, All commands are

testing them remembered.

as you go

SET;

L0G=OFF De-activate
logging.

G;C3 Get the list of

commands.

ED Edit your program.

Pemember to put
STOP on the end,
and ensure you
delete any mistakes
you made in
keying.

AS;R;page Register your new

number program.

PlPS-lll is designed as a full

system to give you the moono to

do all normal business tasks as
easily as possible. Automatic
Programs extend the power of
PIPS so that you can automate the
jobs that you do. However, some
task may be too complex for PlPS-
lll to handle easily, or they may
have requirements for speed or
communications which PIPS
cannot handle by itself.

A special version of Basic called
DBASIC 111 has been created to
get over this obstacle. With
DBASIC-III (the "D" stands lor
"Docking") you can write
programs in normal BASIC which
process the date in PIPS pages in
any manner you choose.

Furthermore, you can compile
your DBASIC program, store it on
the PIPS program disk, and call it
up *rorn within PlPS-lll using the
command: DK#PR0G where
PROG is the name of your
program.

Thus you can write your own
custom routines to do such jobs
as communications and data
conversion to/from PlPS-lll pages.
Anything you can do in SORD
BASIC can now be done from
within PlPS-lll itself.

0€GINN€RS

Getting

loops

straight

Basic BASIC 6

By GORDON FINDLAY

Continuing a series on BASIC
for complete beginners.

Loops are so common in
programming that almost all
programming languages have
special statements for coding
them rapidly and easily. BASIC is
no exception, and this installment
will look at the FOR statement.

Here is a simple program with a
loop. Type it in, remembering to
make any changes your machine
expects (putting in LET, for
example.):

10 X = 1

20 Y = X ■ X

30 PRINT X; " ";Y

40X = X+1

50 IF X < = 20 THEN GOTO 20

GO END

Let's analyse it: lines 20 and 30
do the real work — between them
they calculate X * X; and print
them out, separated by spaces.
Line 10 makes this happen with X
having a value of 1 at first; line 50
makes it happen again and again
until X becomes 20; and line 40
makes sure the value of X
increases by 1 each time. Lines
1 0, 40, and 50 together make up
the loop.

Every loop has a "first" value, a
"last" value, and an

"increment", or step. In our
program above, the "first" value
is 1, the "last" value is 20, and
the "increment" or step is 1. Try
changing one or two of them, in
lines 10, 40 or 50.

There is a neater way: BASIC
provides the FOR statement.
Modify the program to look like
this:

1 FOR X = 1 TO 20 STEP 1

20 Y = X • X

30 PRINT X; " ";Y

40 NEXT X

60 END

The FOR statement in line 10
has the first, last and stepping
values, and the NEXT X statement
shows where the loop ends.
These two act as a pair of brakes,
as it were, enclosing the lines in
the program which are repeated.

In most machines, the STEP 1
can be left out if the stepping
value really is 1. So line 10 could
become:

10FORX= 1 TO 20

Even if this is so, you must
include the STEP phrase if the
increase is by some other value.
Change line 10 tc read

10 FOR X = 1 TO 20 STEP 0.5

Now X is increased by 0.5 each
time round the loop, so more
values are produced.

Here is another program to try.
Work out just what is produced,
then try with a machine and see if
you were right:

10 FOR Y = 6 TO 25 STEP 0.25
20 Z = 2 • Y
30 W = 3 * Y

40 PRINT Z, W
50 NEXT Y
60 END

There are a few things to
remember about FOR-loops to
prevent disasters. Actually, these
restrictions are true for any sort of
loop, however constructed, ft is
just that they are easier to express
and more obviously dangerous in
this case.

Firstly, don't miss out the NEXT
statement. If you do, the rest of
the program will be included in the
first interaction (first time round
the loop), and then the program is
finished.

Secondly, name the correct
variable in the NEXT statement.
Some of the better versions of
BASIC can make do without the
variable at all, but even then you
must be careful not to include the
wrong one.

It is often sensible to jump OUT
of a FOR-loop, but it isn't very
sensible to jump IN. If you do jump
in, what is the value of the looping
variable to be? Now I know it is

THE N.Z.
COMPUTER
GAMES CLUB

CALLING ALL HOME
COMPUTER and
HOME VIDEO GAMES
SYSTEM OWNERS

MEMBERSHIPOF THE N.Z. COMPUTER GAMES
CLUB MEANS YOU CAN:

1. Hire comput?r and video games to try in your home
before purchasing.

2. Hire games on a weekly basis at a fraction of their cost
and exchange for different games when you wish.

3. Purchase games by mail from the largest selection in
N.Z. at discount prices.

Fill In The Form Below For Details Of Cost, Titfes Avai fable Etc.

Post to : THE IN.Z. COMPUTER GAMES CLUB.

P.O. Box 93, Rangiora, Phone 6200 Rangiora.

Name _^ __ —
Address

ATARI

aoO/400

ATARI
CX2fiO

APPLE

Sirs 80
THS80 I

PET

VIC 20

WC22ARD I

zxei

TUNIX

FOUNTAIN

ORBIT COMPU

31

>lr

• PRO-WRITER

• -WRITE FOR

. YOUR COMPUTER

: T

C. Itoh't PRO/WRITER gives
high quality dot matrix
printing at low cost.

Features high density

proportional characters
ideal -for correspondence.

With 10. 12i 17 chars/inch
BOLDcd CD i_j b 1 e under 1 inp
character & dot graphics.

Fait -J20 chars/sec -logic
seeking -3000 char bu-f-fer

Sheet paper feed - letters
& forms tractor standard.

Interface options -for all
na intromesi minicomputers
and microcomputers.

10" width SO-136 char/ line

MocJol SS i OA
15 H width 136-231 char/ line
Mode 1 i SSO

Available from:
CED Distributors Ltd, Ph. 486-200, Auckland.
• Leading dealers throughout New Zealand
• N.Z Distnbutors

MICROCOMPUTERS

55 Upper Queen Street. Newton, Auckland.

P.O. Box 68474, Auckland, New Zealand.

Telephones (09) 773-389, (09) 793-619

TWA 1?0dB

B€GINN€RS

possible to fix things to make
jumping in work, but there is
always a better way.

FOR-loops are often found
nested. But if they are, the inner
and outer loops must never cross.
If you think about it, you should be
able to see why — after all, what
would the value of J be in line 70
in this incorrect skeleton:

10 FOR J = 1 TO 10

20

30 FORK = 10 TO 20

40

50

60 NEXT J

70

80 NEXT K

The program needs a value of K
in line 70, but since K depends on
J and line 65 is outside the J- loop,
K cannot have a value . Th is is only
one of the sort of things which
can happen with crossed loops,
and they are outlawed
completely.

One sure way to prevent nested
FOR-loops from crossing is to be
sure the NEXT statements come
in the reverse order to their
matching FORS.

Here is an example of a program
with correctly nested loops — all it
does is prints out the
multiplication tables:

10 FOR I = 1 TO 10

20 FOR J = 1 TO 10

30K=I'J

40 PRINT I, "x";J" = ";K

50 NEXT J

60 NEXT I

70 END

See how the J-loop is totally
inside the l-loop, not crossing it.
Now a job for you: modify this
program to print a multiplication
Table in the usual sauare form.

From page 21

transfer time differences cited

would be far less apparent. The

lesson here is that your peripherals

and network should be on the same

speed plane. A super-fast network

running slow peripherals is wasted

money.

6 Can I change the machines I use

on my network

The user's dream is a network
that any microcomputer can attach
to. The reality is thai commerwal
pressures have encouraged the
manufacturers to specialise their
Continued page 35

32

SINCLAIR

Equation:

Winning

program

"Equation" is for a Sinclair
2X81 with 16K RAM, and unex-
panded ROM.

This is the winning program in
"Bits Si Bytes" competition No. 1 .
It is by Wayne Dobson, o/ Katamv
High School, Hastings, and won
him a Sinclair ZX81 supplied by
David Roid Electronics.

When "Equation" is run the
name of the program and the
writer's name are displayed. Then
the program goes into an example
showing movement keys, how to
play, and the point scoring. That
goes away and the computer
simply displays in the middle of
the screen, "Push G to PLAY". If
G is not pushed then after a while
that clears and an example of the

high score being written yjp j 3

shown. Another "Push G to
PLAY' ' is displayed and if G is not
pushed then the cycle starts
again.

Note, however, that if there is a
high score it is displayed (just
before the program's name) with
the highest scorer and the holder's
age.

If G is pushed then the screen
clears and you are asked to push
either N for novice. I for
Intermediate, or E for expert.
Novice has a fixed height for the
equations to come from and a
slightly longer time to answer the
question flines 2130 to 2140). In
intermediate, the equations can
come from 4 different heights (line
3009) and the player has a shorter
period to answer the equation. In
expert, the player has a very short
time to answer the equation and it
can come from eight different
heights. To stop people from
working out a system the answer
ship (your ship which is
controllable) comes from different
places.

The game section — when playing
the game the question will appear
(addition or subtraction) and top.
The player must then hold down

the key (0 to 9) which answers
the question until the scores at the
top change and the answer is
written up where it is to be
displayed, Then the question
starts moving end the player by
moving the answer ship (an A at
the bottom of :he screen! using
keys 5 <1 TO THE LEFT), 8 (1 TO
THE RIGHT) ar,d9 12 TO THE
RIGHT) must position himself or
herself ahead of the question and
by using key (zero) must release
the answer from the ship in time
for it to move up the screen and
connect (if possble) to the end of
the question (scoring shows
points and misses).

Five misses is the end of the
game and the highest scorer is
allowed to put your name and age

up.

N.B. failure to answer the
equation correction or push
answer up at ship results a miss
also keys must be securely held
down, not Just taped.

Wayne .has suggested the
following amendments to his
entry:

Add -
5Q03KHINI Al 0.21;C;ATQ,21;" "
5005 PRINT AT 0.21:C;AT0.21;" "

Change linos —
2167 TO 2169 and repine© 2167 with the
original 2 1 69

3167 TO 3169 and replace 3:167 with the
original 3 1 69

4167 TO 4169 and rtpJflce 4-167 with the
original 4 1 69

The program

1 & 10 Copyright, nane and writois name.

date prog was written.

30 sets high-score to wto.

40 chocks to see if thjio is a high score, it

POl jump to line 160.

42 to 1 50 Displays high score, high scores

holder, holders age.

160 to 290 Displays frog's name, writer
and month & year written.

300 to 960 Draws a mock scmhwi and
game as in the- pictures ol a novice game.
970 10 1020 asks if you want to play.

1 030 to 1 300 shows you whet to <Jo if you
get the high score.

1310 to 3340 asks if vou want to piny.

1350 Loops back to 40-

140O to 1630 asks you to choose a class

(N. I. or El.

2000 to ?460 is the rovice section.

3000 to 3460 is trw intermediate soct*on.

4000 to 4460 is the cupon section.

5000 to 5160 is for a high score to> be

written up.

Variables

A BS as a decimal nuTtber

6 Score

C Hi -Score

E Score this turn

F Height of e-Quau-on

G Used to play Game

H Column of answer ship

I & J Used 1or loops

K To givo a number deciding if the

equation is + or -

t High score holders age

M First factor of equation

N Second factor of equation

O Sum of oquation

Numbet of misses

T Movement of equation in example

7 Movement of -answoi in example

AS 31 11 lino) ol spaces

BS Used for answer to equation

CS Hi Score holders name

OS "4 +5=" for example

ES Numbers for "A" movemoni in

oxamplo

F9 Number 9 for example

Difficult linos to read

2450 print at 8.0; AS : at 1 8,H; " " - one

space.

2460 go to 2005.

3460 print at 8,0; AS : at 1 8.H: " » - one

space.

3460 go to 3005.

4450 print at 8.0; AS; at. H; '* " — one

space.

4460 go to 4005.

1460 lot 0=0,

ia - = .■ - ■ ■_-'_■- : . 3ii — e ■■-• mb

UBSC?V f.O'. IS'iJe

. - ■■■ -.
■

L a tf C - ■> tiii - - 1.

~z phxmt *t- 0,i0, ■ i «-•

>KP •■ -:.■-■--
ii Fr:? v ' flr - -.' --* <■

15 FR1MI' -IT ?. 1£ > •

• a femur nr «..-..*. .--■

" IMT AT ?,-*;•'■ il*» *■" •-

■ ■ • - • • '

63 PftXMT RT ••■:' ■ • ■

Tfl -^ITl BT " - - • ■ *

. KSHT »r IQ,J," - .

*»a wsiht sr ii. a;- .** ... ,

ii-j RfUtfl HT iSfii'-HSkB BY"

s^c rcii.r «- i6,*.R(

3.30 PR JUT *vr IS , CI "ACE "si,

34o pop 1=0 to iSa '

3ro HOT I

JM HW Ni-ME

ibs prxnt «r a.» f "eouHrjgt(KBWR.T

1M e=int mo 9

aa» *>»X—T THP ?

aiO PRH4T TSO 3

-jo caim iri? ^

.:-*0 »^IMT T«D 3,

.rue is. -o-
TfiB za.-H-

;tpb aa;-o

, Iho 83; "I"
iTSis aa

' WfitSUHT IQUCOU 1

fitiuaTiwi"
' by urvue R r-

n^o ps;mt or 3.191

ioO PRJIlT DT 13,?:

S7D PRINT THB 1 1. "NJOVCHBER 19B3

aoe voo x»o to 3ob
2C0 HEXT I

iOO -EM CXBMPl-C

aa p;?it«r -scom-B-.-RT t.n. ■■■-..

-SCORES" CRT O ._•*. I'lISi;;. -o

330 Fttxtrr r« 1.0; 'BtoBi: t»ii> tu

■HaO "T 1 ,iO. -flriSUER-"

310 F=;i*r mi zi.o - j.u;.:j=tio»i by
u r DtiB:-Q'* Jue?-

D3B PRINT HT SB ,0: "LCFT-S' ,Hf S
O . IS. "HIBUT i -? . — «i**'

Soa p^iHT jr •,?;"lHtSH o to pla

V

37B PRIHI TRO 9, -UIlCH niKBO"

399 t-xr ot-- i»a«"

Sao CillMI MT 0,0.0*
4QB KOU I-O TO a
*IB NEXT Z

tafl PBTMT Hr 1,87,0
*2s »-c^ 1 -a to a

*SB tET H-IO

4KB po;Mt RT 18 .Hi* A ■"

*70 POP I -1 TO *
■1211 l-*-T a««"VS33"

iSO IF liitl) r"V)" THEM (-HT M-M*9

BBS JF EIIXI o-B" THfiN 1.KT M-H- S

ae= =." till) s-a- then t_ET m-ii.;

»1B PBIMT AT e,3.D«
B3« EBIhT «T 13. M." R

■so rc- j-e to s
3+0 HKXT J
330 HE'T 1
|"; -=t XmXT

u /a i.Ei 1 ■«

33

SINCLAIR

-,- .. . . ■ ■ ,■ ■--■■■-■■■

■3-jO Jllr THEM PRINT AT Z4-1,H

nats H.ET F«-"»
aao IF ; il

*a

bo print *t z,n-a:#*»

OIJ FRiNf HI U. t .D«

eae let t-t*.i
BDfl TDK I"0 TO B
Bit a »ie*t j
n-ja urt r«z-i

DOB IF Tfal*. THEN COTQ SBC

£70 PHIMT AT 11, Si"* POXNT3-
osa pom i-o to 3o

?IS..p5'int>t IW ' + ♦« "r"T 3

'tiB PRINT BT 11.3;"* POINT*"
7io for i-o ro so
■730 HE XT 1
■?*n i ff-imtp-T •.!*;•• **»- -.o: =>

'-789 print *r iijor-a points."

7fr.U FOR I. a TD 3o

: - 1 !! r.r -.- :

ii

at 0,3,*;

4*5-

-T ■

.....

ip.n^ paint rnp o. -rt •novice " . -*n

o i-;m l«mcd i*Tt -,3rt& b; *e-E;%p£

1KC3 IF 1NKCV*>- N - OR II^LVIr- I
OH It.XEY.-~E- THEN OOTO 1665

*.£»* SOTO 1603

16B7 PRIHT RT S .0,H ■; Ra-.A.- *5
^&ttf IP |H«V»»V TMEM OOTO JBC

2
iGAU IS 1HKCYI-' I" TMeNl QOTO 3BP

193* X' JMKCY1- E THEN GOTO 400

en •«»houic=» *»
LET g,

"?B0 PRINT RT 11.3: ".a POINTS"
soo '■on x-e to ao

aitO HSXT 1

->i0 PRINT AT B.14,'* &•*■ ";«T E

'aii ^nlMT »T 11.?; '1 POINT "

eae row i-o to db

■ 50 ■ . r ■- t I

36e_PRll«T_ftT 3.1I.'9i<5- " - BT »

'*7» PRINT AT ll,3f"0 POINTS'
BSB "OR X-O TO 30
-Bi> HBVT T

Bed ffiivr »»t a.ia,- 9 4i-5« *",bt
a, 13, - -

IIO PRI-.T XT 11.3,-NISS
9iO rCP S»C TO 30

090 WBXT ;

>.* Fa. kit «ir 0.13:" I -5 - 9" ; AT

ft'o f ok :-e TO 3co

,■ ■ - • 1

■g=cri p'ifllt TO PLAY

fc*NT > .1 ". PUBH TO Pi.

icieo t -i i-a tc 303

.. - INKBt •-'J" IHLN OOTO lis"-

- •".■•'I- L3 >:■-"• 9-CCKO

- ■ C-*
:o3tf pwjhT e*r"M*»i.B

L3EC ■•■ ■ u. CCM0»OTULor:c

AT 7,aj"'V0U HfflVE THE

- -^ - =I.IT»B VflUH"

la&s ■ :■-'■ • •• il .a, "NMMt'-

io »or. r-o to jiv
UK f mr m .-:.«. -u".
: .-;- ,-3. 'AVHB POO»C«a"

'CR Ial TO 11
: \ao p;p jio TO s

: ice- --.::.■ > s 1 ;.

liCJ FUXMT l»T ai .0. •■

1193 PRINT «T 11.6,-UnYWt POMOM E

jaea ■ ;:«r at 13.»;-roe-
;."".? rn;HT s» ai .0. 1
isas ren^ijo to *

brimt'at ai .0:1s
iase por s-o Tp »

1574 PWJMT AT 81 ,0;

i.ifia nnifiT at 13,*;'"13"
IB "on i»o to soa

i->iaHR;ri PUSH O TO »UHV

vs»o roR 1-0 to »oe

1330 IF IHhtV|»-0" TMEH GOTO 1*-C

a

13*3 MCXT I

13B0 -^TD 40

1*31 PCI1 •••UMMCltl

14 10 CI. 3

L41B ttiT HO-0

laaft (-ET fl-fl

143P LET B-O

1+60 v-cr B»Q

1*73 IET OwO
14S0 t.PT M»C
1 i«3 UET X-O

tsoo LBT JbD

j.6 IO i.m k»B
LH30 ler m.b

!■«• VET 'i-i-

tSBO LET o«a

1BSD OfllNT "8COne-".BT d,u;-hi-

»CORE»-:AT »,g*. -HISSES g"

1S7B SHJNT AT 1,0, "SCOW THIS TL'
BN»" mT IiIP-i "ANSUER«"

asee print bt ai,o,-u«»«iMo.vou

1f.UE OliL-V 3HB CHONCe"

1-.9D PPX-HT BfT B.B/'C-OOSC VOOP C
LMV

aeao priiit bt a,o.fl» __

= 007 PRrMT AT 1 ,S7; "iAT io.m;"

cOU i_bt KiiKT rRxoaai

■fiBB ucr Mazrn* irhdhioi

eeao let m-iki crno>*io*

= U31 PBIHT RT 0.6;O;AT 0,»l,CiRT

o.3i;d;ot 1 . 1&-E

BOAe IF K-9 T-Ih LIT O-H.M

QC9S0 IP K-O AND 0)>10 THEM OOTO

4BS4

2360 IF K=l THEN LET 0«M-M

Si^iTP ir K»l AHP Ol -P TMtN -OOTO> »

BBS

SOBO UET M*3KT {P>IC*«13* -IO

SaSfl PRXNT RT 1S.M, "»"

5100 L.ET 2-1

£110 IF KaB THfn PRINT HT (t.*;M;

-♦■■;r*; "■'.

aiae if k-i thin print at d,Z;m,

£130 FOR I>3 TO- 3B

B13B LET r-|r!!,".f.|

illO IF B»»"- THEN NEXT I
2160 Lf— ' n-CoDB P« OB

2;6D IT RiO THEN UCT C »C • 1
iie^ let j.e.E

i;6&- XF O.C Tufftl LET C -0

2ie? if hot n-o> <dih lbt t»-o»a

siea ir a.c- tmeu lbt c>i

£-69 PRINT «1T 1,10;E.AT O.O.fi.PT

c.Ji.c.ar O.ii.O
ii79 IF Q,<3 T1E^ OPTO SOtf".'

S17B TF NOT A-Oi THEN OOTO 3*3©

-=;ac p")iht **t ; . .- 11

I19B =;■— — "1 TO J7

aaoj ip k-b rp>EH priht hi b.z,**

B210 IFK.l TMBN PRINT AT B.ZS"
- H; - -'-,Nj " ■"
=315 LET fi:K
^.-iO LET H>M- . I'-t-.E". »■■■«"> • «!'■■ ■-'

ii-i-i • i:nkev»*"|-» - 1 junen**^ — ■
i?2I IP H>93X T«P!< LET M«311

c22H if M-. -O TMBN L.ET rt-O
3383 IP HOT H.O THEN L-CT MO-1
2339 IF INKBV*- '•" TMOiN LBT ■»-!«>

S210 IP A-IO T"=H JOTO *3JO

=;5H PK2NT RT 10 ","«" . _

E?e>e if MQ-i tmcn ««iht at is .a

iZfS NE.VT Z

aaes • ct aso. 1

flSSO COTO Ji>00

23iSO LET MT.17

a.-.OS IF ".»& THEN PRINT AT 9 . i ,

£310 ir f.ml TMCH PRSIT ht t>.Z."
■; m: "-'■fN* ~ ■"

;--is uc \ : ~: - ;

£33D if rti.iV T.iBH prim* *T 11TH

.H: M '

23«© PRINT RT HT.MJO

2Z-SO LET MT>«T-1

ia&e If HT>-3 T«H GOTO a JOS

ETT? IF MT-T AHD M-Z-4- IMEN L«tT

! = !o 6 IP NT ^7 H»*D r»-2.3 THLh LET

i;sa if KT"7 awo N»£«a then let

eXgO IF MT = 7 HC.O N»Z«1 THEN LET
sXlO^:^ "T-7 MHO "-~ Tilt" LET C«

Illc TP MTa7 ««S HI Z-a TliCM .et

--30*:> MT-7 "iWO H<-^-3 l"KH LET

0-0 • J
3440 LET B>B-e —- — »,■

2*43 PRINT AT l,ie,E;HI B,6.l>

£^4* IF OlC THEN LET O-l

B**C IF 8»C TMBN LBT C -B

344.S IF O.-S T»«EH OOTO TIDCV

VAZ BESS " S;o;«. ; mt *»,«>- ••

"-ISSMSrraiMBefflTe.*.

o pftiNT'ni e.o. h«;r«.a«;R»;R*
300 7 PRINT RT 1,W; U ";AT iO,H,

saoa i_er r«:nr m»«p**> »7

3310 LET «3!NT IflHOiat
£b£3 LET M=IMT IBMP.IO)

3030 LET M = lt.r iRNP*lgl
aOSO IF K-B TMEh LET 0-ll»N

2%SX ir K ,° RNC- 0--10 THEN 3Of0

-ypa CT

3«r>(i ir K-a, TMEh LOT O-M-N

3JB70 IF K»l "WD O.-B TMCN; OOTO 3

■■■■-■ '

Bail LET M=M* iIHKEY|»"9"JtlI'«rr
■"§--1 »I1MKEV#--«"J -IIHKBVB--B"!
3^£1 IF H>-31 THEN LET M-31
^^;j IF M«=0 TMENI LET M^W
-■355 IF HOT HiS TMEH LET MO-1

:"c IF IN-EV#."B" THEN LET h -ltS

3840 TF R=10 THEN! OOTO 3300
JO^O PRINT PIT lfl.M,"fl"

piJF, E F HO»l TMEH PR3NT HT 10. P>

33 '0 NlffxT- Z
3aBO LET O-u-- 1

33 OO GOTO 3l«0a

33 OO LET HT-17*

-JB5 XF K=0 THEN PRINT RT F , X; "

3310 IF'Kil'THEH PRINT AT P.I;"
33B& LET &«Z»1

3'130 XF HT'S? THEM PRINT RT MT»i

;?ie print at «T,h;0

33 BO LET rCT-MiT-l „„

33BP XF MT.«P TUCH OOTO 3SOS
■M>rO XF MT'P-l AMD H«IM THEN IE
T EaBaS

3380 Jr HT=r-l PWD tt»Z»3 THEN LC

T CrC.l

33-90 ZF HT.F-1 AND " -Z -J THEN LB

T EaC+a

34eO IF HTaF-1 AND H.I"J fnflN LaT

T C:C»a

34.1Q XF MTaF-1 RNO *1=Z THeil LET

CiCtl

ji.-. 1 :r -it ■"-; -no ns-Z-a Then ».
kt o *a • 1

34 30 IF MT-F-1 RNJO •• .■ - Z . b > -(■ n »,

CT 0=0*1

3140 LET OiBtE

3443 r>RiNT nr i,t6,t.UT i' > . if

24.41 XF E>JC T:?C. L£T 3-.

.". 1.:= IF BiC THEM LET C'D
m(K — Z~" O > m* TME»J OOTO SCOO
?i-47 "RIWT AT O.B1.C

515P ra^MT A- S.O.UB.&T IB M '

Jlfiif i70T0 300-B

4000 ~Z" •»*E''<Pfi-ir»« •

<tac? — ET EiO

10O6 PRIHT AT 5 .»?. HB ..:•■■*. Mt -'■■4

^s: r*;a«

4307 PRINT FIT 1.3*7;" " , HT 10,M;'

■iffOB LET r=INT .HNDiOI'9

JMP LET K-IMT IRIJU-J)

iOJl) L=T I'-IIIT lRHD-il«)

403O '—TTT H-1IJT iRNOalOi

*O*0 Zr K=P THEN LET 0*I«tH _^__

Al>=0 IF Pi =0 RNC. C.-IO THEM UOTD

ti~r '

4»bO IF K=l IMEM LLT 0=M-N

•P76 ir «=1 AND O'.-O T«1£H OOTO 4

4030 LEI M.Ii^T .RNSJl'-l . It

4Buo r-BZiiT bt ia.ii; •*•>'

ilCO LET 2=1

41.10 3P P--0 TMEH PRINT «T P«Z{nj

(ISO IF K=J THEN PRINT HT F^ZiM;

ii.30 jwi 1=1 ro as

4k35 LET B*-I'ME.'|

f.lO IF D* = "" THEN NEXT I

4l.se LET A-CODE of-aa

1 IT IF O-O THEN i_ET 1 -•- - '
4-.OS LET D:B*E
ilea IF D>C THEN LET CO

iiGT IP H-OT H;0 THEN LBT 0-Ofl

4TOO IF O-'C THEN LET O-S .

*lo« F-AiNrr rt i.i«,e;~7 d,6;»;AiT

o.3i;C;DT a r 3i.o
4i7fl IF 01 .»5 THEH 00-ry b80Q

417S IF MOT «-0 THEM GOTO 4-tSB
4.130 PRSMT RT 1,37. A

dlBO FOR i*l TO 37

IF K.»0 TMEN PRINT RT P , Z;

3000 Lcr n-wr ;KMOti^;«io

5llO IF K.te TMEH PRINT MT T.Z.H.
2i-£B N IF _ Kal TMEtl PRIHT AT F.ZlH;

" -"; n; ■•-■*,

31310 F?H 1-1 TO -r
3135 LET BI-INKCVB

J140 IP tlla " TUCH HOI 1

3150 L£T •"• -CODE BB-aO

Sl&O IF O^D TMEU LIT C-E.l

;.?? let sse.e

-•-.E-6 IF I«>C THEH LET C.U

S1E7 IF HOT AaO TMEN LET O-OaX

a ai C AT Q,31-D

ilia "IF O ' -C TC'" OQTO Bt90O
3173 IF NOT A«0 THEN OOTO 3*E>0

31O0 PRINT AT i.a?:R

3190 'C» 2"1 TO J7

33aa IF K=B THEH RRINTT HT F..;

3£XO If'kIi TMEN PRIM' RT F,=."

4310 IF K-l THEN PRINT RT F.Z;"

-;m; "-■';«; -a"
*;;;y let O-h

4SSO LET H-H- lINI\E-/»-"0 *l - t 1NKBY

I»"3*'l HlNKEYi-"9"> -IINKBV»-"B"i
331 IF HJ-33 THEN LET H-31
-.;._.; IF Hi'a THgN LET H-O
4»5 IF NOT HiO THEM LET MO » 1

•Vl-30 I* INKE3Vl-."0" THEN LET Ralffl

J-JiO IP R-IO TMEN OOTO -1390

4USQ PRINT AJ 1B,H;' N '

*B0D ll " NO" 1 THEN PUIHT AT lO.Oi;

4 a 7© NEXT Z
43DO LCI 0-0»l

crJUJ GOTO 40OO

4300 LET MT=3,7

4303 IF f.*0 THEM PRINT BT r,I'"

- :M, "•-,«: "•"

4310 IF Kil THEN PAINT RT F,Z;"

•*vM; - --,m; "a—

4sao let z-z-i

433B ir rfT(17 TMEH PRINT RV Ml « 1

,m; - ~

'"» POIWT at ht,n;0

43BO LET HTaMT-li

4 360 IP tfT>.F TMEN OOTO *3»fl

43<"0 ;r HTsr-l RNO N-2*4 ThIIii k_a
T B-C-B

4300 ir MTsr-l UNO rt-Z*2 TNCN L.C

4393~ IF MT=F-I HNO FI>Z>a TMEN LI

4433 IP HT=P-1 RND M«I*1 TMEH LE
l4l6 C XF KT.r-1 »NO H*Z TMCII LET

4430 IF MT-F-1 RND M'aZ-a TMBN L
ET O-Otl

4430 IF MT"F-1 RND Mi-I*S TMEN L
ET 0*0*1

34

SINCLAIR

BOOKS

iiffnmijniw"'i'

44*11 LET Q.B + R

4443 PRIMI AT 1 , IS ; K ; (*T 0.6;B

C4t* IT BiC THEN LC7 & = 1

Ui 1 - IF O'C TMCM LC C-D

44*0 ir ©>-s t«cn ooto seee

4*47 print bt a,ai;c

443a BRjHT bt e,o:«i:«T IB -H; »

i*(.0 SS»TO 4-OOB

i91JB"L-| iiiNFU HIOM 5CORB»»»
1MB TOW I«* TO 1B0

saia next 1

SD3B IW~NOT ami THBH OOTO 48

bp*(9 prSHT AT ■.Bl-eOWOROTULCTTIO

yeso print bt 7, a; 'vou houe tub
MIUM SCORE"'

snr>o print rt o,a; xnteo vour-
■07* print rt aa.»;~NRMi ••;

S3BG INPUT C»

5C-BO PRINT C» „„__ „

eiao print bt 13, a-, hoc
enu incut 1.
013U VPIMT »T JJ.Tit
313© FOR IbO TO Si>

aiT>a CLft

3103 GOTO -"O

ftBrrWftVj^tfuyrt'Wv^ ^^i^W'*"i%w-W^i»w*v^rt^a*v^*A»rty' W*v^ -**v^ ■

From page 29

the book is the depth to which
particular "standard" program-
ming problems are developed.
One of the familiar tasks allotted
to the programming student is an
analysis of sort rates using various
methods". This text provides a
comparison program which will
appear like mana from heaven to a
student required to produce such
a scheme. The sorts examined are
the bubble sort, dried and slow!),
insertion sort, inssrtion sort with

APPl€

A tip for Apple users

A reader, G. PORTENERS, of
Paremata, offers this hint tQ

Apple users

You may be courting trouble if
you are using the RENUMBER
program of APPLE II PLUS
SYSTEM MASTER (DOS version
3.3 08/25/801. Try the following
listing:
tOQ-A'20
20 R = B*20
30 END

Renumbering this by command &
F= 5 results in:
5Q = A'15
15R = B*15
25 END

The factor 20 in lines 10 and 20
assumes the value of the
renumbered line 20. If, however,
you write the expressions with the

numerical factor first, i.e. Q = 20*A

and R = 20 r B, all is well. I had this
trouble in a program which used 240
HPLOT N, SIN(A) *80 + 79. On
renumbering the original line 80

changed to 100 and so did factor 80
to produce $IN(A)M0O. I have now
changed the expression to
80"SIN(A) and havs had no further
trouble.

From page 32

networks. Having hooked you they
have you. Having said that, there is

on C3COp«. Most machines can be

made to converse with limited
flexibility through serial ports (this is
fine for occasional data transfer but
limited in every other way). The
light is that there are a few networks
coming in to production which
allow far greater -flexibility, and this
may be a significant purchasing
factor. One networ< manufacturer,
Omninet, was predicting a network
capable of linking 23 different sorts
of machine. There are limitations
still in such an arrangement though.

• Next month, Nick Smythe will
look at networks which are
available in New Zealand.

binary search procedure, shell-
metzner sort procedure and the
quicksort procedure. The second
point about these programs is that
they are written so that the reader
can utilise them as procedures in
their own programs-
There are a number of other
programs which may also be of
use to a new Pascal programmer
who has as yet not built up a
library of routines which might be
needed. Linked list procedures, a
label print routine, character
conversion routines, a simple data
base with editing procedures, and
even a pseudo-random number
generator.

As a collector of esoteric
routines that everyone writes as
an exercise at one time or another
I found the book immediately
interesting, but. and there is
almost alway a but . . .

The layout of the text, which is
blocky and unattractive, the lack
of space and diagrams
combined with the newsprint/
paperback quality of the materials
used makes the book initially
seem less than it actually is.

In summary, it is a book which
does not patronise the reader and
expects that the reader has a
modicum of experience in
programming and has probably

undergone a series of formal
programming exercises in BASIC.
It presents a library of common
procedures that can be
incorporated into any

programming work without undue
modification. Its presentation is
not attractive but this is
misleading. Perhaps the final point
I can make is that I am pleased to
have a copy — it will be useful!

M

OUR COMMITMENT

to help you before and after the sale

Sinclair

We stock

* lots of software

* some incredible books

* computers you can afford

* we give advice free

Commodore
VIC 20

write

or call

Asbfbrd TV Rentals Ltd

166KEPA ROAD. ORAKEI. AUCKLAND. BOX 6870
PHONES 583-570. 583-293

35

CDITIPUTflSHDP.

_ >

-*? .

.;

NZ's Widest Selection of Personal Computers
monitors, printers, disk drives

"2X-80 'Vic 20 *Hawlttt Packard

•A»n 'Sy»«m 80 'BBC MICRO

"TRS80 Color Computer

* Osborne • Epson HX-20

rt* look forward to your tfisft. Write 'or Msil Orders.

Oedit Gndt Accepted

EINSTEIN SCIENTIFIC LIMITED

177 Willis Street. Wellington
PO Box 27138 Ph 851-06& T» NZ33SC

41icro^ge(|ilcf@Pro) D =i 0R

* WordStar S595 * SperlStar $322 * HaiWerge

* DalaStar S440 * CalcSiar $380 * RepirtStar

IBM PC ANO APPLE FORMATS AVAILABLE

MicroAge International (NZt Ltd
P.O Box 13054
353*357 HerotorcJSt.
Christchurch. Phone 89 1 -1 09 .

S216

S410

! M!ti!J!» amBSB P^

computer point <n.z.> Ltd
•W sinus

Christchurch
P.O. Box 25-091
phon* I1-27B

Zilog

NJZ. Arjonla for ISE/PACTEL's MDBSIII Data Baae Management Syatom
Network apeciaHata - ECONET - ETHERNET - ALTOSrTET - CP/NET

KAYPR0 II Portable Computer
COLOMBIA MPC 16 Bit Computer

Sole South Island distributors

TURNERS Ltd

P.O. Box 1021 Christchurch

Phone 794-820

FOB THE LATEST IN MICROCOMPUTERS

COMMODORE 64 & VIC20
ATARI t*t*m

SINCLAIR KT

EARN 74'/*% INTEREST WHILE YOU SAVE
149 HEREFORD STREET, CHRISTCHURCH PHONE 797-279

(Opp. Reserve Bank)

JAMES ELECTRONICS LTD

POLLEN ST

BOX 527

THAMES

Ph 86893

Games tariff I Inserts 8k trap)

Snake-Ma iris Game- Bull I'i Bucket

Gii<mistapc2 Cno«xpreq<M

Formula 1 ■ Concentration- Lini< G;iiiil'

S15eachpbpS-l

Al&o available for VIC?0 Payroll and

Casebook programs. Writ* tor details.

COMPUTASHOP
COMPUTASHOP
COMPUTASHOP

Computashop is a low-
cost way of reaching BITS &
BYTES readers.

You can save up to 55 per
cent on usual advertising
rates.

Remember every BITS &
BYTES reader is interested
In computers — i.e. a
guaranteed audience for
your computer business or
product.

Computashop,
BITS & BYTES,
Box 827,
Christchurch,

Please support

BITS & BYTES

advertisers

■,:

BBC

^mWWWtWPW"™**"***"*

dumw h hm ii— i— w

-■■*

Beeb

has Speed

By Pip Forer

Straining (he deadlines and the
editors' nerves to the limits just to
get a glimpse of the first
"Computer Programme" before
this draft article gets sent off. It
seems that the BBC and IBM have
at least one thing in common
(apart from each having three
initials). That common thread is
the realisation that the greatest
barrier to computer adoption is the
newcomer's nervousness in the
face of technology- Charlie
Chaplin and a red rose and Chris
Serle's matter-of-fact probings
provide the same ingredient;
reassurance. Whether you prefer
the slick symbols of one or the
personal approach of the other is a
matter of personal taste.

IBM also come into this column
because this month we look
hriefly at the basic model D Deeb
and ask just how good it is in its
native tongue, BASIC. There are
two approaches we could take
here. One is to catlogue the merits
and problems of BBC BASIC. The
other is to benchmark the BBC
computer against various other
machines.

In general, BBC BASIC has been
well received. Although its unique
features will not transfer to other
machines the combination of
procedures, in-built assembler
routines and powerful commands
for handling Input/Output rather
make up for that. VDU, OSWRCH
and FX not only let you do things
wefl within a BASIC program but
make conversation with other
machines that much easier.

BBC BASIC has been well
covered in reviews elsewhere so,
for the moment, further
discussion of that aspect is put
asido, Instead we will return to
benchmarks and (indirectly) IBM.
What is a benchmark? It is a
timed series of operations on a
computer, usually used to
compare the processing power of
one machine against another. The
task defined within the
benchmark forms the basis of

comparison. Thattaskcan be very
simple (and pretty stupid). A
common first benchmark is to run
a null loop, i.e.

10 (or i = 1 to 1000
20 next I

For clarity you usually insert a
print statement at the top (Ready,
Steady, Co) and another at the
end announcing the programme

has finished. Then if you have a
stopwatch you settle back and
time the task. 01 course, if you
have a BBC you us the TIME
command to do this for you. The
command

5 TIME «

sets the clock ;ounter to zero

and

100 X =TIME;PRIN~ "BENCHMAHKEO
TIME": X/100;' SECCNOS"

prims out the final lapsed lime

for thn tpst

There are a few things to say
about benchmarks. Firstly it is
normal to run several on a single
machine. This is because certain
machines do sone operations
more quickly than others. A
second test might be to add

15G0SUB 1000
lOOO RETURN

just to see how last subroutine
calls work. A machine fast at null
loops may be slow at subroutine
calls (and one fast at both may be
slow with rea'ly important
instructions). The benchmarks
usually therefore seek to test
different aspects of a computer:
setting varrabe- values,

partitioning string variables, doing
trigonometric functions, doing
normal maths operations. A
favourite is to fiid the prime
numbers between 1 and 1000.
Since disk drive access time is
frequently a large part of running
time many benchmarks also
involve disk access time by
reading and writng randomly
generated values to disk files.

Different publications publish
and use different tenchmarks in
their evaluative reviews. Three I
know of are those from
"Australian Personal Computer."

"Interace Age" and "Byte". How
does the BBC Computer behave
on some of these? The "APC" of
December carried a list of 49
machines it had benchmarked. It
used seven different programmes
and averaged over these. They
tested various aspects but had no
disk access tests. The BBC came
out as the second fastest. With a
benchmark timing it ran through at
14.6 seconds. This compared
with the slowest on that list, the
Texas Tl 99/4A with 78.2, the
Apple 11+ with 30.4 and the IBM
PC with 17.6. The significant
update since then has been the
release of the Apple He with a
reportedly much-enhanced clock
speed. A comparative benchmark
with this machine would be
interesting.

Interested by the December
benchmarks I ran the "Byte"
benchmark used in a January,
1982, review of the IBM PC on a
BBC machine. The figures are
given below. Thoy arc for
resident, non-compiled BASIC in
cither machine. The BBC machine
figures are for a locally run
benchmark, the IBM ones taken
from "Byte," January. 1982,
page 54.
Benchmark IBM BBC

1 Empty do loop 6.43 3.28

2 Division 16.80 23.80

3 Sutxoulino jump 12.4 5.34

4 Substring (MID* I 23.0 T1.75

5 Prime Number 1 90.0 Out o'

■pKO

I was unable to run the last
benchmark fully since it requires a
7000 element array. The BBC
machine has not enough memory
to cope with this so we had to
omit it. Nonetheless, the figures
are quite interesting. Why do the
differences emerge between
machines, both here and in the
"APC" table? First, factors
include the efficiency of the
BASIC and the dock speed of the
processor in the machine. The
BBC machine outdistances some
other early 6502 machines simply
because its clock speed is cranked
up to 2 megahertz. Some
machines suffer because the
BASIC interpreter they carry has
been poorly tailored to the
processor thoy use. One thing that
seems to emerge from most of the
comparisons is that, at least for
8088 based 16-bit machines such

37

BBC

r*v*fftt**mer * Ti<*jvft*f*™

as tine IBM PC you buy not for
speed but for ease of handling a
relatively large memory. Actual
interpreted BASfC speeds suggest
8/16 bit hybrids such as the
8088-based machines are slower
than a fast 8-bit machine but
marginally faster than earlier 8-bit
ones.

A word of caution, however.
The "APC" table listed three
8088 based machines with
reported speeds of 1 7.6. 20.9 and
24.8 respectively. That is each
was roughly 20 per cent faster
than the next. Running other
benchmarks on the same
machines locally suggested that
the slowest and fastest were
equivalent while the middle
machine was about 25 per cent
adrift of these two. The
conclusion: benchmarks are
useful only as rough guides, and
at that as rough guides only to
speed. For many users that may
be no guide at all.

However, it is nice to have the
power off a fast system if you need
it. The BBC machine scores well

on litis tor OAGIC application^;.

However, one problem came
straight to mind . . .it ran out of
RAM. After all, benchmarks are
designed to run on most machines
and their demands should not be
overly excessive (even if a 7000
number array is quite large).
Available memory is the Achilles
heel of the BBC machine as first
released. To see how this arises
and how it can be countered by
additional paged memory or a
second processor read on in May.

CLASSIFI€DS

FOR SALE CHA.LENGER IP. 8K
with Cassette Tape Recorder,
software and manuals. 5 500.
Contact Mrs J. Wood, Cambridge
High School* 5415.

WANTED Cash Flow, General

Ledger accounting and farming
software for SORD Ml 00 Ace.
Contact J.R. Stevens. 6A Euclid
Street. New Plymouth. Phone
39-472.

FOR SALE

SURPLUS COMPUTER
EQUIPMENT
IBM model 2770 RJE station
with 2213/2 printer and 2502
card reader.

DEC RK07 Disk Drives 28Mb
(formatted) (two units)
DEC RK61 1 Disk Controller
DEC DZ11 A4B 16 line EIA
controllers.

APS C30 6800 based

microcomputers (3 units)

IBM and DEC equipment under
maintenance agreements.
Available now.

Contact: The Director

Computing Services

Centre

Victoria University

Private Bag

Wei ington

Ter 721-000 Ext 703

VIC

From page 25

then takes them from there to use
them on a first in, first out basis.

Our changes mean it doesn't use
the buffer. It simply stores the Ns
and Ys as we pushed 'hem and
leaves them tbe'e in the buffer.
Normally the VIC stores 10
characters in.the buffer and if these
aren't used, it ignores an>y extras.

What we want to do is stop ihe
VIC from storing any keys during
the game. We can do this by
poking the location that controls
the number of characters stored.
This location is 649. Try adding

:P0KE 649.0 to line 20 and ;POKE
649. 10 to line 220. That should
solve the problem.

Now if s your turn to take ovar
the process of refining the program.
A few suggestions - try making the
bat a different colour from the ball;
add another bat and make it a two
player game. You could either play
tennis, second bat on the left, or
squash, second bat at the same
end.

If the game is too slow for yOu,
change line 50 or perhaps allow lor a
variable to be input and then used in
the timing loop. The possibilities are
endless. Have fun!

CUSTOM WRITTEN

PROGRAMS:

FX702P, FX602P, System

80/TRSSO, APPLEII, VIC20,

and others. Other System 80

software also available. Write

with stamped self addressed

envelope for information to:

LINC

36 Bruce Rd.,

Glenfield,

Auckland 10.

ZX81 users: I would be interested
to swap software (educational
software if possible). T. Daniell, 8
John Street., Rangiora.

Exidy Sorcerer equipment. 48K

computer, display-disk, S-10O
expansion, ROM Pacs, D/A-
A/D, tape recorder, EPROM
eraser, etc . Will sell any or all to
first reasonable offer or best
offer by 30/4/83. Telephone
Wellington 723-494.

ZX81 + 16K printer $350 Ph
796-606 (Wellington).

FOR SALE System 80 $800 0M0.
16K. with sound lots of software.
Phone Auckland 453-540.

WANTED: 80-micro back issues.
1980: Feb to May. 1981: Jan to
June. Sept & Oct. Please sent
issue nos & price to P. Clare, 8
Norway St, Kelburn, Wellington,

FOR SALE one 8K RAM pack, for
the ZX81, includes reset button
and power on LED $80.

ZX81 FOR SALE ONLY $169wiin

transformer and manual. Write 59
Wesley Street, Kaiapoi.

Casio FX-9O00P for sale $900. As
advertised in February 83 issue.
S. Jasper, Hilltop. Ohai, South-
land.

PROGRAMS for small businesS|
and personal computers written or I
modified to your specifications-
Phone Paul Cull ChristchurchJ
327-807.

38

CLUB CONTACTS

.,.:> , ..--.-■

WMAMGAREI COMPUTER GROUP: Tom All-an.
3 Mmou Rd. V/luMwjvtl. Phone 83-063 (w>.
Meets every second Wednesday of the
mciifi 11 NonNnid Conununitv CoUeee.

NZ MICROCOMPUTER CLUB IMC. P.O. Box
8210. Auckland. Tho montMy Meeting is
head on Iho first Wednesday ot eacn month ai

the VHP Clulwooms. Kaiel Av».. Mi Rosfc*.

from 7.30pm. Visitors are alto welcome to

the compute' workshop in tho clubtoomv

lOum-Som, en the Saturday following thn

above meetiiH).

The foHcwirg uwf groups art paft of th*

club. Ai meetings s"howi start 7.30pm at the

VHF Oubroom.

Other active user g*oups- wtthkt the dub eft:
APPLE. CP/M. DREAM 6800. SMALL BUSINESS.

KIM, LNW. SOftCEHER. 180? and 2650.

Thoy can all be contacted at cl ub meetings or

vie N2 microcomputer Club. P.O. Bon 6210.

Auckland.
APPLE USERS' GROUP: Biuco Given, 1 2 Irk-angi

Rd,. One Troo Hill. Phono 667*720 (hi.
ATARI MICROCOMPUTER USERS GROUP: Btlan

o' Dean Vak.ii. Phono 8363 060 lh>.

Meeting*: Second Tuesday.
BBC USERS' GROUP: Dave ftetder. Phone

770-630exi 518 (w).
EUG BOARD USER GROUP: Steve Van Veen, flat

S. Ill Maltose Rd. Ml Ac-skill, Auckland 4.

Phono (09) 6*9-991 ml.
BUSINESS USERS' GROUP: John Hawthorn. 1 1

Soavtcw Rd. Rornutrt. Phono 642-714 im,

876-189 iw). Meetings monthly.
COMMODORE USERS' GROUP: Ooug Miller, 18

Wetdone Ave., Glonliold. Phone 4.44-961 7

lh|. 497081 <wl. Meetings: Tlv.d

Wednesday.
CPM USERS' GROUP: Kerry Koeperi. 2 670

Oorrwitctn Rd.. Balmoral. Phono 69-5350 *ti».

Meetings: M.co workshop.
DREAM 6800 USERS: Polo- WMm ">0 KWcion

St, New Lynn, Auckland, Phona 109) 8751 10

(M,
KIM USERS: Jo*m Mirn. 1A Norihooro Rd.

TaAapun*. Phone (09) 4S7-8&2 Ihl
LNW USERS: Ray James. Phone 109) 30-839

Iwl, 585-587 <h),
SINCLAIR USERS' GROUP: Ooug farmer. Phone

667 689 W. Meeungs: Fou-th Wednesday.
SORCeniR USERS' GROUP CNZI: Sehvyn Anew.

Phone 491-012 Ihl. Meet*>g>: Micro

wotiiinop.
180? USERS' GROUP: Brien Conquer. Phono

6S6-984 (h|.

The above contact* can usually be found at
N7 Microcomputer Cub Moot noji. or via P.O.

Box 6210, Auckland,

Olher Auckland-based groups:

ACES (Auckland Comcuter Education Society):
Pay Ciaske. 1 Ouftdas Pi-. Henderson. Phone
836-9737 Off.

CMUG iCombined M.cocom>pj:er Users' Group):
This >s an assoc-atic-n ol Vtcioco-npuior
Clubs. Groups, etc. formod to ca-orCinate
activities and to Qlvo a combined voice on
topics concerning sj| rnKFO men.
Rootese ntation don a) Clubs and Croups b
welcomed ;o: CMUG C- P.O. Box 6210.
Auckland.

EPSON HX20 USERS' GROUP. Contact: C.W
NrQhy, 14 Domett Avenue. Eofcn.
Auckland (Ansaphone. 774 268).

HP41C USERS" GflCU? (Auduervl): O-
Calculator Centre. P.O. ftp. 6044. Auckland:
Grant Bvchansn. 790-328 IwjI Meets tn*d
Wcdnoioay. 7pm. ai Conua Computerc.
Great Sodth Rd., Eesom.

NZ TRS80 MICROCOMPUTER CLUB: Ola!
S«arsho>t. 203AGodley Rd . fnirangi. Phone
8178698 (hi. Meets tint Tuesday, VKF
Cl*jbrooms. Hazel Avo., Ml Roskttl. Auckland,

OSI USERS' GROUP lAkl: Vlnca Martin-Smith.
44 Murdoch Rd.. Grey Lynn, Auckland.
Moots third Tuesday. VHF Ctubtooma, Hsiel
Ave.. Mt fiosia.

SYM«*00l INZ SYM USER * GROUP): J.
Robertson, P.O Box 580. Manure**. Phone
2S6-21B8 ihl.

A.2..T.E .C: Etnan Mayo, Church Street. Katikau.

Phone 4BO-326-. Member) use ad rricros and

the dub has just bought a WW* erd.
TAURANCA SINCLAIR COfVTUTcB CLUB: C.

Ward. Secretary, P.O. Bo> 6037. Brookfiold.

Tauranga. Phone 82 962 or 89-234.
ATARI cMjBOO USER ClUB: Oevo B.own. P.O.

Bok 60S3. Hamilton. Phone 1071) 54-692

<ht.
GISBORKE MICROPROCESSOR USERS' GROUP:

Sluari Mullen -Merrick, P.O. Box 486,

Gisborne. Phono 98-028.
ELECTRIC APPLE USERS* GROUP. Noel

Bmlcjcnan. P.O. Boi 3H)5. Fitzruy. Ntv*

Ph/mouth- Phone 80-216
TARANAKI MICRO COMPUTER SOCIETY: P.O.

Box "7603. Bc5 Block. New Plymouth: Francs

Slate.. Phono 84-514.
HAWKE'S BAY MICBOCONPUTfR USERS'

GROUP. Bob Brady, Prim* Phjrmacv.

Plnma. Plaza. Napier. Phon* 439-016.
VOTORolA USER GROUP: Harry Wiggint,

(ZL2BFRI. P.O. Box 1718. Palmorston Norlh.

Phono I063I8Z527 !h).
MICRO AND PEOPLE IN S0CI6 1Y IMAPS): levin.

meet* on second and fou-th Ihufs-Jav Of

eech morith. 0. Cooe. 29 (rV-burgh Stieei.

Levin. Phone 83 904. or W.Wrtnel. P.O. Box

405. Lcvan.
ATARI USERS' GROUP. tVelngton: Eddie

NicklMs. Phone 731-024 (wl. P.O. 'Box

1 601 1 . Meetings: lirst Wednesday of month.

CENTRAL DISTRICTS COMPUTERS IN

EDUCATION SOCIETY: Roiy Outlet. 4 John

Shoot, Levin. 1069) 84-466 or Margaret

Mofflan. 18 Slandon Stiwt. K.«o*i.

Wolainflton. 104) 767-167.
UPPER MUTT COMPUTER CLtO: Shane Ooyie.
18 Holdworth Avenue. Upper Hutt. Phone

278-545. An aa-macheie d«*b.
BQC USER GROUP: Useis ol oth*r machifw*

welcome ton Write P.O. Bok 'SO!.

WeUington. or Phone 861-213. Wekrnion.
0S60RNE USER GftOOft Dr Jb> Baxtaxa. &• »6

Ghumco Street. Wollingtor 1. Phone 104)

728 658.
NZ SUPER BO USERS' GROUP: C/- PeBnwt

Computers. 5 Oundoo PI., Chartwefl,

Wellington 4. Phone 791-172.
OHIO USERS* GROUP. We*ngtc*>.

Stcretaryi'Irca-suftf: R.N. Mo*op. 658

Awetea Street, Porirua
WCLL1NGTON MICROCOMPUTING SOOETY

INC.: P.O. Box 1681. WoBington. or BWH

Patkin (h) 725-086. Mcot>gt ate held m

Wang'a BUiUaX. 203 203 VYVL* Slfccl, on

the 2nd Tuesday each month at 7.30pm.
NELSON MICROCOMPUTER aUB: Dr Chrrs

feltham. Marsden Valloy Rd, Nelson. Phone

(054) 73-300 {hi.
NELSON VIC USERS* GROUP; Peter Archer. P.O

Box 860. Nrfsen. Phono (05*. 79-362 In).
BLENHEIM COMPUTER CLUB: CM> night second

Wednesday o* month, van Meyne4i.

Secretary, P.O. Box 668. Phxva lh) 05-2O7

Of (w) 87-834,
CHRISTCHURCH ATARI US:ftS GROUP:

Contact Edwin Brandt. Pborn 22e 222 lh),

793 428 (w).
CHRISTCHURCH "80 USERS* GROUP Dev4d

Smith, p,0. Box 4118, Chrirctiutch. Phono

63-111 IN.
CHRISTCHURCH PEGASUS USERS' GROUP:

Don Smith. S3 Farn/.rars 'd. Redwood.

Cnnstchurch. Phone I03> 526-994 (hi,

64-544 iwl, ZL3AFP.
CHRISTCHURCH APPLE USERS' GROUP: Pawl

Na U atei. C- P.O. Etox 1472. Coristchu'ch.

Phono 79-6-100 Iw).
OSl USERS' GROUP (CHI: Barry Long. 377

Etttnngton St., Sgf«T*)n. Chfti-.-.

Phone 384-560 Ihl.

CHRISTCHURCH SINCLAIR USERS' GROUP: Mt

J. Mitchell, Phone 385-141, P.O Bo.

33-098.
eHRISTCHUHCH COUMODOftE USERS*

GROUP: John Kremef. 885 533 and Jorvi

SpaffOw, Phone 886*039^
ASHBUnTO>JCO.V:PtJIEPSOCfEIi-:Mr J Cie*.

52 Orucehckl Avenue-

SOUTH CANTERBURY COMPUTERS' GROUP.

Ceten (ot «■ machines for *fx8l to IBM34.

Geoff MeCaughan. Phone Twnaiu 34-200 o-

P.O. BOX 73.
LEADING 60GE HOME COMPUTER CLUB- ElB'ne

On. Leading Edge Computet s. P.O. Box

2260. Ounedm. Phone 55 ?68 (w|.
DUNEDlN VIC USERS' GROUP: Terry SHand. 24

Bromnct Road, f#tf*w Phono (024]

801-432. Meetings last Thursday ol month.
DUNEDIN SORD USERS' GROUP; Terry Shond.

Phono (0241 771-295 M, 881-432 (hj.

NOTE: Clubs would appredaio a Clamped,
stff>r*Wte«ed cnyoJooc with any wntien inquiry
to them.

NOTE: if your chiti or group la not itsled. drop
a lino with the data's to: Club Contacts. BITS &
BYTES. Box 827. Chrai crunch. The deadline lor
additions end attetst-ons is tho second weekend
Of tho month before iinj nt^nt 'iV'"

N€UJ PRODUCTS

A portable computer to rival the
Osborne 1 is now on sole in New
Zealand.

Like T.he Osborne the Kaypro 1 1
folds into a carrying case,
although at 26 pounds it is two
pounds or approximately one
kilogram heavier than the

Osborne,

Tho Kaypro 1 1 luis x Z-80
microprocessor, 64K RAM, a 76
key detachable fcoyboard (with
numeric keypad), an RS-232C in-
terface port and Centronics
parallel printer port and twin 5%
inch floppy disk drives with 191 K
of user memory on each.

Probably the most significant
difference from the Osborne is the
screen, The Kaypro 1 1 has a 22.9
cm (9 inch) screen (measured on
the diagonal) displaying 80
characters wide by 24 lines com-
pared to the Osborne's 12.7 cm (5
inch) screen.

Also like the Osborne several
software packages are included as
standard in the Kaypro 11V
$4690 price tag. These are CP/M
disk operating system. S-BASIC
(the "S" stands for structured), a
word processing program called
Select (and a disk called Teach
which explains word processing
to the first time user) and Pro-
fitplan, a financial/calculation
spreadsheet program again said to
be oriented to the first time user.

New Zealand agents for the
Kaypro are President Computers
of Auckland. We ■will have more
on the Kayporo 1 1 in a later issue.

39

GLOSSARY

BASIC: Boginnors' All purpose Symbolic

InstrucOofl Code. The mut widely uwd, Hid
easiest to loam. h>gh level programming
language (a language with English-like
instructions) for microcomputers.
Binary: Tho system of counting in t's and Or's

usedbyalld^iial computers. Ttw l's andO* 1 ?

are represented In the computet by electrical

pulses, either on or o".
BJt: Binary digit. Each bit represents n ctwact-er

in a binary number, that is either a 1 or 0. The

number 7. initials 10 in Pinery and is :ac bits
Boot: To toad tho operating system mio the

computer from a disk or tope. Usually one of

the first siepi m preparing the computer for

use.
Bug: An error in a program.
Byte: Eight bits. A letter or number is usually

repfoeoniod in a computer tiy a eeilos of eight

bits called a byte and the compute' hand**

these os one unit or "word".
Character: Letters, numbers, symbols nd

punctuation mirks «ecn of which has a

specific mean«g in programming laoguawes.
Chip: Ar> Integrated circuit etched on a tiny piece

of silicon. A number of mieg'atefl circuits are

used in computers.

CPfM: A disk oparatingj system available for
micrtKOrnputora using a particular
microprocessor (that is the 8080 and 280
base-d microcomputers such as the TRS 80
and System 80). Sec also Disk Operating
Systems.

Cursor: A mark on a video that indicates where

[ha next character will be shown, or where a
change can next be made.

Data: Amy information used by tho computer
either i'O or Internal information. All internal
Information is represented m btrtary.

Dili: A flat, circular magnetic surface on which
the computer can stoce and) retrieve data and
programs. A flexible or (loppy disk is a- single
8 incK nr 514 inch disk of flexible plastic
ondosfd in an envelope. A nam disk is an

assembly of several discs of hard plastic
materia*!, mounted or* above another on the
some spfnafe. The ierd disk holds up to
hundreds of millions of byies. - while floppy
disks cyp-cafly hold between 140-.000 and
three million bytes.

Disk drive: The mechanir.el device which rotates
Ute cask and positions the read/write head so
information can be retrieved or sant to the
disk by the compute'.

Disk operating system: A set of programs that

operate ond control sne or more disk drives.

S"0o CPi'M for one example. Other examples
ate TRSDOS ion TRS SO) end DOS 3.3 (for
Apples).
Firmware: Programs fixed In a computer's ROM

I Read Only Memtrvl: at compared to

software, prograrrs held ouisride the

computor.
Hardware: The comparer itself and peripheral

machines for storing, reading in and printing

out information.
Input: Any kind of infrrmation thai one enters

into a computer.
Interface: Any hard wore/ software systnm thai

links a nWcrocompoicr and any other oevtce.
K: The) number 1 024. Commonly refers to 105*

bytos. Morn exception is capacity of

ntMAaaj chips, whp<c k mean* tQ24 hits.

KILOBYTE (or KJ: Represents 1024 bytes. For
example 6K is 5120 bytos 16 x 10241.

■s a B h fctl language* The binary code language
that a computer can directly ""understand*'

Megabyte Cor Mb): Rapotients a million bytes.

Memory: The pat of the microcompuTer that
stores Information and instructions. Each
piece of information or instruction has a
unique location assigned to it within a
memorv. There it internal memory inside 0>e
microcomputer itself, and external memory
stored on a peripheral device such as disk s or
tape.

Mtofocomrxiter: A small computer rwisea on n

microprocessor.
Microprocessor: The central processing unit or
"intelligent" part of a microcomputer. It is

contained on o single chip of silicon and

controta oil tho functions and calculations.
Network: An interconnected group of computers

or terminals linked together for specific

CO mm unic ation t .
Pascal: A high- level language that may

eventually rival BASIC in popularity.
PEEK: A command that examines a specific

memory location and gives the operator the

vnlue thore.
Peripherals: All externa! input or output devices:

printer, tetminol. drives etc.
Pixel: Picture element. The point on o screen In

graphics.
POKE: A command that Inserts a valuo into a

specific memory location.

Program: A set or collection of instructions

wmien in a particular programming langu-Jfte

that cauaes a computer to carry out or

execute n given operation.
RAM: Rcndorn access memory . Any memorv into

which you "read" or call up doto. or "writn"

Ol enter information and instructions.
RBrl statement: A remark statement in BASIC. Jt

serves as a memo to programme*, and plays

no Dot or the running program.
ROM: Read only memory. Any memory n which

information or instructions have been

permanently fixed.
Software: Any program* used to- operate a

computer.
System: A collection of hardware and software

where the whole is greater that the sum of

tho parts.
Tape: Cassette tape used fo>r the storage of

information and instructions (not music).

Word: A group ol bits that am piocessad
together by tho computer. Moat
microcomputers use eight or 16 bit words.

Casio's A ll-in-On e Personal Computer FX-9000P

— S990.00

SAVE $805 ON NORMAL RETAIL PRICE

By direct mail order only to:

Auckland Business Equipment Ltd,

P.O. Box 4399, Auckland.

NAME

ADDRESS

Please send further information on how I car take
advantage of this offer

Options to refine or expand
FX-9O0OP performance

MKand 16K RAM Packs with/without

battery backup.

'Three expansion ROM Packs.

"0P1 for printer and cassette

interlace plus clock/alarm

with battery backup.

'0P2 twin floppy disks and RS323c interface.

* MX82 Graphic Printer. * FP1 Mini Printer.

All optional extras purchased with original order
qualify for 25% discount off normal retail price.

FX-9000P

40

Verbatim Datalife 3 flexible disks
now come in a bold, new storage bo*.
But more important, they now come
to you with a Jive year warranty* .
We can give you a warranty this
Long because we're confident the way
we make Datalife disks will make
them perform better, last even longer-
All of our Datalife disks feature
seven data-shielding advances for

greater disk durabil ity. longer data
life. To protect your data from head-
to-disk abrasion.To shield your data
against loss dueto environmental

conditions. Toensure a longer

lifetime of trouble-free data

recording, storage and retrieval.

Every Datalife disk is extensively
tested under the most extreme
conditions. Critically-certified to be
100% error-free. Assuring you an
added margin of performance, no

ma«erwhat He operating conditions.

And we back it up with a five years

warranty. Five times longer than the

industry standard. Because Verbatim
is the standard of excellence.

M

Datalife

Verbatim®

Here's the most exciting
part of Verbatim's new

For flexible disks you can depend
on— a lot longer, call 109) 444-6085

COMPUDATA MEDIA
SYSTEMS LTD

Bo* 3273, 4K EIHce Road, GlenficM. Auckland

'

Here is the news .

The B.B.C. has arrived

"Firstly the machine has been laid out with a clear growth
path in mind: you can see how [he design has room for
expansion.

Secondly the machine as it stands is highly flexible. Il
possesses the 'openness' of the Apple plug-it-in peripheral
card philosophy, the screen software flexibility of the Atari
400 and 800 machines and the teletext compatibility of Poly.
Finally il seems to have taken all the little edges that most
current machines possess, rounded them off and then French
polished them."

Dr. P. FORER in Bits and Bytes
November, 1982

B.B.C. Micro

The face of things to come!

FACTS THAT MAKE THE
BBC BETTER

•Price. .. is competitive... $1995

• Good Colour essential for

entertainment and in presenting
information, you can highlight
different areas at the same time.

• The resolution of the screen allows
640 dots x 256 dots which makes the
BBC the best system available at this
price. When making Graphs and
curves, the better the resolution the
clearer the curve.

• Sound. . . four sound channels, three
note generators, one noise generator.
Full sound envelope control on sound
channels. Is. adaptable to have a voice
synthesizer fitted. The production of
the sound does not stop or delay the
running of the central process.

• Basic. . . allows the use of
PROCEDURES and REPEAT UNTIL
loops, which give it the advantages of a
structured language.

• The BBC model B is the computer of
the future. - - U is able to be hooked up
to a second processor when necessary,
the Z80 and 6502 already released. The
BBC will never go out of date! A.16 Bit
Processor to be released soon.

it EDUCATION

£ TRAINING COURSES AVAILABLE
:, ON SITE DEMONSTRATIONS
u HOME DEMONSTRATIONS
& FULL TECHNICAL ADVISORY

SERVICE

' GAMES/ENTERTAINMENT

Distributed by:

Access Data Ltd Auckland Phone 686 578

Branches in CHRISTCHURCH and WELLINGTON — and authorised dealers.